SIMES Field Budget Reports-June 2015

Transcription

Stanford Institute for Materials and Energy Sciences (SIMES)
Field Budget Request for FY2016
FWP
Page
Time‐Resolved Soft X-ray Materials Science at the LCLS & ALS
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Diamondoid Science and Applications
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Electronic and Magnetic Structure of Quantum Materials
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Correlated Materials – Synthesis and Physical Properties
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Spin Physics
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Clathrin Biotemplating
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Magnetization & Dynamic
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Atomic Engineering Oxide Heterostructures: Materials by Design
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Two-Dimensional Chalcogenide Nanomaterials
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Joint Center for Energy Storage Research (JCESR)
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Nanostructured Design of Sulfur Cathodes for High Energy
Lithium-Sulfur Batteries
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Pre-Lithiation of Silicon Anode for High Energy Li Ion Batteries
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Field Work Proposal – SLAC National Accelerator Laboratory
SIMES: Time‐Resolved Soft X-ray Materials Science at the LCLS and ALS
Date Submitted: 6/18/2015
FWP#: 10017
Time‐Resolved Soft X-ray Materials Science
at the LCLS & ALS
Principal Investigator(s): T. P. Devereaux, Z.-X. Shen, Z. Hussain, Tony Heinz, A. Lindenberg, D. Reis, and W. Mao
Staff Scientists: Wei-Sheng Lee, Yi-De Chuang, Mariano Trigo, Hongchen Jiang
Postdoctoral Scholars and Graduate Students: Crystal Bray, Martin Claassen, Jesse Clark, Frank Chen, Simon Gerber,
Thomas Henighan, Te Hu, Shigeto Hirai, Chunjing Jia, Mason Jiang, Michael Kozina, Yu Lin, Shenxiu Liu, Ehren
Mannebach, Christian Mendl, Clara Nyby, Dylan Rittman, Renee Sher, Michael Shu, Kai Wu, Peter Zalden, Qiaoshi
Zeng, Zhao Zhao
Overview:
This program connects concepts of ultrafast time-domain science with those for momentum- and energydomain x-ray spectroscopy. The FWP consists of the single-investigator small group research (SISGR)
program (Devereaux, Lee, Shen, Moritz, Hussain, Chuang) on time-resolved soft x-ray materials science at
the Linac Coherent Light Source (LCLS) and the Advanced Light Source (ALS), merged with the recent
addition of high pressure studies (Mao), ultrafast activities (Lindenberg, Reis) on non-equilibrium phonon
dynamics and phase transitions, nanoscale dynamics and ferroelectric oxide ultrafast processes, and ultrafast
optical studies of 2D chalcoganide materials (Heinz). The combined activities bring a synergy to explore how
materials behave under extreme conditions, driving lattice and charge conformational changes by applying
short pulses, high fields, or high pressures. The purpose of this research is to develop a world-class program
on the dynamics of complex materials using the x-ray beamlines available at LCLS to address the grand
challenge problems of “emergence”, non-equilibrium dynamics, and to probe model systems for deep insights
on materials for energy conversion, transport and efficiency.
Theoretical calculations and simulations conducted in parallel with experimental progress will establish a
formalism for describing non-equilibrium physics of strongly correlated and related materials and provide
additional guidance to experiments. This activity requires the development of novel theoretical and
computational tools and as well as the deployment of standard techniques designed to uncover the nature of
the many-body state both in and out of equilibrium.
We have made substantial progresses on several research fronts to advance our understanding of complex materials
through advanced x-ray based techniques coupled with advanced numerical simulations. These include LCLS- and
synchrotron based experiments to further the study novel quantum materials and extend knowledge of time-domain
based x-ray spectroscopy. In the following, we outline our progress through lists of bullets.
Progress in FY2015
LCLS-related activities:
 We have performed the first pulsed magnetic field experiment at LCLS to study charge density wave (CDW)
state in YaBa2Cu3O6.67. With this new experimental setup, we investigated the CDW evolution up to 28 Tesla,
significantly higher than previous experiments. Surprisingly, in addition to the CDW already existing at zero
field, we observed another CDW correlation emerges at high field and low temperatures. Its field and
temperature dependence are consistent with the NMR observations that have been attributed to the CDW state;
thus, they likely share the same origin. Furthermore, our results directly reveal that this CDW is three
dimensionally ordered with a propagating wave vector different than that of the zero-field CDW.
 We have directly characterized the photo-induced coherent lattice dynamics in a parent iron-superconductor
BaFe2As2 via time-resolved x-ray scattering experiment at the LCLS. Combining with theoretical investigation,
we evaluated associated changes in the band structure, Fermi surface, and magnetic properties. This work has
been accepted for publishing on Nature Communication. (S. Geber et al., Nature Communications accepted).
 Recently, we performed a continuation experiment to further investigate the temperature and doping
dependence of the photo-induced coherent lattice dynamics in BaFe2As2 and superconducting compounds,
Ba(Fe1-xCox)2As2. We found that the oscillation amplitude exhibits an interesting temperature dependence that
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appears to be only associated with the spin-density-wave phase. Furthermore, a phase shift is also observed at
low temperatures. Data analysis is still in process. During this beamtime, we also characterized the ultrafast
coherent lattice response in a related compound FeSe film ( of thickness of 60 u.c.), grown by Dr. Moore/ Z. X.
Shen group in another FWP. A complementary time-resolved ARPES measurement to directly reveal the timeevolution of the electronic states is also in progress by Dr. Kirchmann/Z. X. Shen group in another FWP.
We have been using the novel capabilities of the MEC hutch at LCLS to conduct time-resolved dynamic
compression experiments. We observed, for the first time, crystallization from an amorphous starting material
under shock compression using in-situ X-ray diffraction (XRD). Time-resolved XRD was used to study the
nucleation and growth of nano-crystalline stishovite grains and determine grain size as a function of time after
shock loading. Data collected up to 33.6 GPa showed nucleation as early as 1.4 ns, fast growth, 22 nm/ns and
find data trends to match a coalescence grain growth mechanism rather than diffusion-based. A campaign on
liquid and crystalline H2O (ice Ih) was successful providing the first shock-driven diffraction data on H2O and
showing evidence of liquid water shock freezing to ice VII by 5 GPa in 10’s of nanoseconds. From our
diffraction, ice X is observed at 1.6 Mbar – helping to bound the onset of the predicted superionic phase. We
have also studied shock-driven plasticity, strength, deformation mechanism, phase transitions, and
resolidification on release in several metals: Ti, Ce, Fe, etc.
Completed studies using both the LCLS and laboratory-scale THz pump-probe measurements demonstrating
giant modulations in the nonlinear optical susceptibility of ferroelectric thin films. This work opens up new
opportunities for electric-field gating of nonlinear optical devices and provides a new understanding of novel
ways in which the ferroelectric polarization can be manipulated by light. Experiments at the LCLS show subpicosecond modulations in the structure factor and indicate a surprising field-driven cooling of BaTiO3 films,
providing a new understanding of field-driven ultrafast electrocaloric responses in ferroelectric thin films.
Measurements at the LCLS showed a new means of visualizing the structural dynamics of semiconductor
nanocrystals, capturing both their breathing mode response and melting response in the limit of large stresses
and strains. These measurements inform our understanding of the dynamical response of materials at their
limits, in the limit of large amplitude strains.
In a series of LCLS experiments on XPP, we have demonstrated high resolution with Fourier transform inelastic
x-ray scattering; using two-pulse coherent control, we have unambigously demonstrated that the mechanism for
generating correlated pairs of high-momentum phonon coherences is through squeezing; and applied the
method to measure the 2-phonon coherent excitation spectra in PbTe, which comprises a squeezed modes in the
form of combination and overtones, and demonstrated the excitation of screened LO-plasmon coupled modes.
Using hard x-ray scattering we have also measured the photo-excited lattice dynamics near the charge density
wave peak in the SmTe3, and in collaboration with H. Durr the generation of high frequency coherent acoustic
phonons during femtosecond demagnetization in single crystal Fe films.
RIXS activities:
 Using resonant inelastic x-ray scattering, we have discovered an unexpected doping evolution of collective
excitations in the electron-doped cuprates Nd2-xCexCuO4. The energy scales of magnetic excitations increases
when doping electrons into the antiferromagnetic ordered cuprates. In addition, another branch of collective
modes is also observed, which emanates from the zone center and disappears at high temperatures.
 Since then, we continue to investigate complete doping dependence of the collective excitations in electrondoped cuprates, especially near the antiferromagnetic-superconducting phase boundary. We have performed
two more RIXS experiments at Swiss Light Source and National Synchrotron Radiation Research Center to
measure samples with different dopings across the AFM-SC phase boundary. Preliminary data analysis suggests
an abrupt change of the magnetic excitations and the zone center modes across the AFM-SC phase boundary.
 Two modular X-ray emission spectrographs have been fully assembled and fiducialized for q-RIXS. The
commissioning performed at BL6.3.2 of the ALS gives a resolving power of 1,600 at 500 eV with the
commercial CCD detector. This resolving power is in agreement with the design specification.
 The q-RIXS endstation assembling is nearly complete, with experimental chamber already installed on the
hexapod. The sample cryostat was re-developed and is expected to be completed in fall 2015. The endstation
assembly is expected to be completed before the end of 2015.
Theory activities:
 Successfully obtained 10M CPU-hours in allocations for computational simulations at NERSC.
 We have investigated theoretical constructions for fractional Chern insulators which possess many-body
interacting topologically ordered states that have potential applications in topological quantum computation.
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We developed a description for pseudospin modification in graphene driven by circularly polarized light.
Performed Floquet analysis of “quantum geometry” effects in monolayer dichalcogenides driven with circularly
polarized light.We characterized non-trivial, topological surface states associated with both sub-gap and above
gap pumping with potential for both future experimental observation/characterization and applications.
Work on high pressures:
 We have been studying the effect of pressure on the structural and electronic properties of transition metal
chalcogenides. We have recent results on a silver chalcogenide, Ag2Se (Z. Zhao et al, Phys. Rev. B 2014),
which has generated interest as potential topological insulator and a transition metal dichalcogenide, MoSe2 (Z.
Zhao et al, Nature Comm. in press), which has generated interest due to their atomically thin structures and
unique electronic states coupling high pressure synchrotron XRD, Raman and IR spectroscopy, temperaturedependent electrical transport measurements.
 Organic-inorganic hybrids form the basis for natural and synthetic functional materials because they can
combine the mechanical stability and electronic properties of inorganic solids with the tunability and flexibility
of organic molecules. We studied the structural and electronic changes resulting from the application of
pressures up to 60 GPa on a two-dimensional Cu-Cl perovskite, through a combination of in situ synchrotron xray diffraction, electronic absorption and vibrational spectroscopy, dc conductivity measurements, and optical
observations. Compression of this charge-transfer insulator yields two structural phase transitions, dramatic
piezochromism, and the first instance of appreciable conductivity in CuII–Cl perovskites at high pressure.
 In addition, we have conducted high pressure experiments on a wide range of energy related materials including
high Tc cuprates and mixed valence compounds, anode materials for Li batteries, bulk metallic glasses, and
upconverting nanoparticles.
 We are conducting ultrafast optical and THz experiments in PbTe to elucidate the nature of the anomalous
splitting of the zone-center soft TO mode which has been attributed to both extended anharmonic interactions
and dynamic symmetry breaking at high temperature. We are extending these experiments to high-pressure to
alter the phonon density of states and attempt to isolate the TO mode.
Structural dynamics:
 Completed measurements probing field-driven switching in phase-change materials. These measurements show
that threshold switching, the first step in the field-driven transition from amorphous to crystalline phase, can be
driven on picosecond time-scales, contrary to existing understanding in the field. Complementary measurements
using the LCLS have been carried out using optically excitation, probing the crystal growth velocities
associated with amorphous-to-crystalline transitions, which have been too fast to resolve in prior studies.
 Experiments using a new femtosecond electron diffraction source have been carried out probing structural
dynamics in monolayer transition metal dichalcogenide films. The measurements, currently submitted for
publication, capture for the first time the dynamic rippling and wrinkling dynamics, showing that nanoscale
ripples with amplitudes of order 1 Å develop on picosecond time-scales, reversible at the 120 Hz repetition rate
of the experiment. Complementary optical studies of related phenomena were published in ACS Nano in FY15.
Expected Progress in FY2016
LCLS activities:
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We will perform a time-resolved x-ray scattering experiment at LCLS to investigate the CDW dynamic in
YBCO. We are hoping to resolve the collective dynamics of CDW induced by single cycle of THz pulse. The
beamtime has been awarded and will occur in July 2015.
Followed by our successful first pulsed field experiment at LCLS, we will continue to further investigate the
surprising behaviors of CDW in high temperature superconducting cuprates. In the next beamtime, we plan to
map out the boundary of the field-induced CDW in the field-temperature phase diagram.
We will apply coherent control techniques to demonstrate for the first time selective excitation of high q
phonons using optical excitation. If successful this will provide a new mechanism for controlling and probing
matter both in and out of equilibrium.
We will apply our new method of fourier-transform inelastic x-ray scattering to measure ther relative roles of
anisotropic electron-phonon coupling and Fermi-surface nesting in CDW systems including HTSC.
RIXS activities:
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Inspired by our discoveries on electron-doped cuprates, we will perform high resolution RIXS experiment on
hole-doped cuprates, La2-xSrxCuO4 near the antiferromangetic phase boundary in the lightly doped regime.
Magnetic excitations and its relation to the spin density wave state will be investigated.
 We are also awarded the first user beamtime at ESRF to perform experiment with the newly commissioned
ultrahigh resolution RIXS spectrometer (energy resolution ~ 50 meV or better). We will use this spectrometer to
investigate the phonon excitations in the RIXS spectrum, which contain direct information about electronphonon coupling strength at different momentum. We have chosen to study single-layer and double layer Bibase superconducting cuprates.
 Commission experiments of q-RIXS endstation will be conducted at ALS. Using its unique capability of high
data acquisition efficiency and continuously variable spectrometer angle, we plan to perform energy-resolved
resonant diffraction and momentum-resolved RIXS measurements on classical correlated materials. We also
expect to perform the first time-resolved q-RIXS experiment at LCLS.
 We plan to explore the dynamic of excitons in transition metal diachalcogenides using RIXS.
Theory activities:
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Continue development of Floquet codes to investigate “quantum geometry” in transition metal dichalcogenides
with potential applications in “valleytronics”.
Continue to refine tight-binding models obtained from ab initio band structure calculations for monolayer
dichalcogenides with emphasis on a Wannier description of a larger number of valence and conduction band
states.
Continued characterization of experimentally realizable topological phases and surface states with symmetry
classifications and predictions for realistic experimental probes.
Investigate “valley Hall effect” applications in “valleytronics” and tuning these effects with changes to material
parameters and applied fields.
High pressures:
 We will continue to work on the dynamic strength of materials under dynamic compression (MEC, LCLS) and
work on high pressure phase transition kinetics in metals and simple oxides.
 We will continue our work on transition metal chalcogenides looking at Ag2X and MoX2 (X = S, Se, and Te) as
well as other interesting transition metal chalcogenide systems like ReS2.
 We plan to study the bromide analogues of the Cu-Cl hydrid perovskites, and also plan to substitute Cr2+ for
Cu2+, switching from a d9 to a d4 electronic configuration. In addition, three-dimentional perovskites such as are
one of the most heavily researched family of materials in recent years owing to their fruitful implementation in
photovoltaic devices.
 We will complete studies on pressure dependence of the electron-phonon coupling and anharmonic interactions
in order to better understand the stability of PbTe and related materials.
Phase change materials:
 Continuation of studies of electric-field-driven switching in phase-change materials. Prior measurements show
evidence for filamentary breakdown processes occurring on picosecond time-scales and we will employ THz
pump / optical microscopy probe approaches to resolve the dynamics within a filament.
 Continuation of studies of ferroelectric thin films, probing switching dynamics within nanoscale electrode
structures. Extensions of this work to two-dimensional perovskite films.
 Continuation of electron diffraction studies of monolayer transition metal dichalcogenide and extensions to
multilayer samples and complex TMDC heterostructures. Application of coherent scattering techniques to
probe strain dynamics and thermal transport processes while reconstructing the dynamic strain profiles and
interfacial transport processes.
 We will apply ultrafast optical spectroscopy to examine changes in the band-structure of 2D materials,
including the breaking of valley symmetry, induced by intense optical fields.
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We plan to continue utilizing LCLS to perform advanced x-ray scattering experiments, including time-resolved xray diffraction, time-resolved RIXS and inelastic scattering, and pulsed field experiments to address the grand
challenge problems of “emergence” in and out of equilibrium.
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Continue investigating the collective dynamics with high-resolution momentum RIXS measurement. In FY2017,
RIXS instrument will energy resolution better than 50 meV will be operational in several synchrotron facilities in
the world (e.g. ESRF, NSLS-II, and TPS). New discoveries enabled by these new instruments are expected. Thus, it
is important to continue these efforts. These efforts are strategically important to the continuation of our FWP, as
well as the development of a next generation time-resolved RIXS instrument at the LCLS-II that can fully utilize the
self-seeded FEL and high-repetition rate.
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We will introduce other metals and insulators into the study on dynamic strength once our techniques have been
validated.
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We will continue high pressure studies of 2D- and 3D- hybrid perovskites.
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We will continue to study transition metal chalcogenide systems at high pressure.
SIMES will undergo its triannual DOE program review November 2015. A full narrative of the SIMES FWP program
will be available at that time.
Collaborations
Bolme, Cindy, LLNL; Caracas, Razvan, Ecole Normale Superieure de Lyon; Chen, David Z., Caltech; Chen,
Xiaojia, HPSTAR, China; Chow, Paul, CIW; Collins, Gilbert, LLNL; Ding, Yang, APS, ANL; dos Santos, A.
ORNL; Eggert, Jon, LLNL; Eng, Peter, APS, ANL; Fratanduono, Dayne, LLNL; Goddard, William A.,
Caltech; Goncharov, Alexander, CIW; Greer, Julia, Caltech; Greven, Martin, U Minnesota; Haskel, Daniel,
APS, ANL; Hawreliak, James, Washington State U; Hemley, Russell, Carnegie Institution of Washington;
Kono, Yoshio, CIW; Kraus, Richard, LLNL; Lazicki, Amy, LLNL; Mao, Ho-kwang, CIW; Meng, Yue,
CIW; Oganov, Artem, SUNY-Stony Brook; Pascarelli, Sakura, ESRF; Shen, Guoyin, CIW; Shen, Howard,
George Mason University; Shahar, Anat, CIW; Shu, Jinfu, CIW; Sinogeikin, Stas, CIW; Struzhkin, Viktor,
CIW; Thonhauser, Timo, Wake Forest; Tulk, Chris, ORNL; Yang, Wenge, CIW. Analytis, J G, UC Berkeley;
Ando, Yoichi, Osaka University; Banerjee, Tamalika, University of Groningen; Baumberger, Felix, U
Geneva; Bluhm, Hendrik, Lawrence Berkeley National Laboratory (LBNL); Chen, Cheng-Chien, Argonne
National Laboratory; Chen, Yulin, Oxford University, England; Chuang, Yi-De, LBNL; Delaire, Olivier,
Oak Ridge National Laboratory; Fahy, Stephen, University College Cork; Freericks, James K., Georgetown
University;.; Fujimori, Atsushi, University of Tokyo, Japan, Greven, Martin, University of Minnesota; He,
Rui-Hua, Boston College, Massachusetts; Hemminger,John C., UC Irvine; Hill, John, Brookhaven National
Laboratory; Hussain, Zahid, LBNL; Johnson, Steven, ETH Zurich; Johnston, Steven, University of
Tennessee; Kaindl, Robert A., LBNL; Kampf, Arno P., University of Augsburg; Kemper, Alexander F.,
LBNL; Krishnamurthy, H. R., Indian Institute of Science, Bangalore, India; Lee, Dung-Hai, UC Berkeley;
Lipp, Magnus J.,LLNL; Liu , Amy Y., Georgetown University; Martin, L., UC Berkeley; Mazin, Igor I.,
Naval Research Laboratory; Meevasana, Worawat, Suranaree University of Technology, Thailand; Merlin,
Roberto, U. Michigan; Mishchenko, Andrey S, RIKEN Advanced Science Institute, Japan; Monney, Claude,
Fritz-Haber-Institut, Berlin, Germany; Nagaosa, Naoto, University of Tokyo; RIKEN Advanced Science
Institute, Japan; Orenstein, Joseph, LBNL; Patthey, Luc, Paul Scherrer Institut, Switzerland; Sawatzky,
George A., University of British Columbia, Canada; Scalapino, Douglas J., UC Santa Barbara; Scalettar,
Richard T., UC Davis; Schmitt, Thorsten, Paul Scherrer Institute, Switzerland; Schoenlein, Robert W.,
LBNL; Sokolowski-Tinten, Klaus, University of Duisburg-Essen, Germany; Shastry, B. Sriram, UC Santa
Cruz; Shen, Kyle M., Cornell University; Singh, Rajiv R. P., UC Davis; Stephenson, G.B., Argonne National
Laboratory; Stock, Chris, NIST Center for Neutron Research; Indiana University Cyclotron Facility; Strocov,
Vladimir N., Paul Scherrer Institute, Switzerland; Thomale, Ronny, University of Wurzburg, Germany;
Tohyama, Takami, Kyoto University; Uchida, Shin-Ichi, University of Tokyo, Japan; van den Brink, Jeroen,
IFW Dresden, Germany; van der Marel, Dirk, Université de Genève, Switzerland; van Veenendaal, Michel,
Northern Illinois University, Argonne National Laboratory; Vernay, Francois, Université de Perpignan,
France; Vishik, Inna, MIT; Yang, WanLi, LBNL; Yang, Wenge, CIW; Yabashi, Makina, RIKEN, Japan;
Zaanen, Jan, University of Leiden, The Netherlands, Zhu, Diling, SLAC LCLS.
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Publications
Peer-Reviewed Journal Articles
1.
Charge Density Wave in YBa2Cu3O6.67 at High Magnetic Fields, S. Gerber, H. Jang, H. Nojiri, S. Matsuzawa, Y.
Yasumura, D. A. Bonn, R. Liang, H. N. Hardy, Z. Islam, A. Mehta, S. Song, M. Sikorski, D. Stefanescu, Y. Feng, S.
A. Kivelson, T. P. Devereaux, Z.-X. Shen, C.-C. Kao, W.-S. Lee, D. Zhu, J.-S. Lee, submitted to Science.
2.
Spatially-resolved ultrafast magnetic dynamics launched at a complex-oxide hetero-interface, A. Caviglia , R.
Scherwitzl, R. Mankowsky, P. Zubko , V. Khanna , H. Bromberger, S. Wilkins, Y. D. Chuang, W. S. Lee, W.
Schlotter , J. Turner, G. Dakovski, M. Minitti, J. Robinson, S. Clark, D. Jaksch, J. Triscone , J. Hill, S. Dhesi , A.
Cavalleri, Accepted by Nature Materials (2015).
3.
Direct characterization of photo-induced lattice dynamics in BaFe2As2. S. Gerber, K. W. Kim, Y. Zhang, D.
Zhu, N. Plonka, M. Yi, G. L. Dakovski, D. Leuenberger, P. S. Kirchmann, R. G. Moore, M. Chollet, J. M. Glownia,
Y. Feng, J.-S. Lee, A. Mehta, A. F. Kemper, T. Wolf, Y.-D. Chuang, Z. Hussain, C.-C. Kao, B. Moritz, Z.-X. Shen,
T. P. Devereaux, and W.-S. Lee, Accepted by Nature Communication (2015).
4.
Asymmetry of collective excitations in electron and hole doped cuprate superconductors, W. S. Lee, J. J. Lee,
E. A. Nowadnick, S. Gerber, W. Tabis, S. W. Huang, V. N. Strocov, E. M. Motoyama, G. Yu, B. Moritz, H. Y.
Huang, R. P. Wang, Y. B. Huang, W. B. Wu, C. T. Chen, D. J. Huang, M. Greven, T. Schmitt, Z. X. Shen, and T. P.
Devereaux. Nature Physics 10, 883–889 (2014).
5.
Direct observation of bulk charge modulations in optimally doped Bi1.5 Pb0.6 Sr1.54 CaCu2O8+d. M. Hashimoto,
G. Ghiringhelli, W.-S. Lee, G. Dellea, A. Amorese, C. Mazzoli, K. Kummer, N. B. Brookes, B. Moritz, Y. Yoshida,
H. Eisaki, Z. Hussain, T. P. Devereaux, Z.-X. Shen, and L. Braicovich. Phys. Rev. B 89, 220511(R) (2014).
6.
Large-Amplitude Spin Dynamics Driven by a THz Pulse in Resonance with an Electromagnon. T. Kubacka,
J.A. Johnson, M.C. Hoffmann, C. Vicario, S. de Jong, P. Beaud, S. Grübel, S-W. Huang, L. Huber, L. Patthey, Y-D.
Chuang, J.J. Turner, G.L. Dakovski, W-S. Lee, W. Schlotter, R. G. Moore, C. Hauri, S.M. Koohpayeh, V. Scagnoli,
G. Ingold, S.L. Johnson, U. Staub. Science 343, 1333 (2014).
7.
Charge-orbital-lattice coupling effects in the dd excitation profile of one-dimensional cuprates. J. J. Lee, B.
Moritz, W. S. Lee, M. Yi, C. J. Jia, A. P. Sorini, K. Kudo, Y. Koike, K. J. Zhou, C. Monney, V. Strocov, L. Patthey,
T. Schmitt, T. P. Devereaux, and Z. X. Shen. Phys. Rev. B 89, 041104(R) (2014).
8.
Melting of Charge Stripes in Vibrationally Driven La1.875Ba0.125CuO4: Assessing the Respective Roles of
Electronic and Lattice Order in Frustrated Superconductors. M. Först, R. I. Tobey, H. Bromberger, S. B.
Wilkins, V. Khanna, A. D. Caviglia, Y.-D. Chuang, W. S. Lee, W. F. Schlotter, J. J. Turner, M. P. Minitti, O.
Krupin, Z. J. Xu, J. S. Wen, G. D. Gu, S. S. Dhesi, A. Cavalleri, and J. P. Hill. Phys. Rev. Lett. 112, 157002 (2014).
9.
Persistence of magnetic order in a highly excited Cu2+ state in CuO. U. Staub, R.A. de Souza, P. Beaud, E.
Möhr-Vorobeva, G. Ingold, A. Caviezel, V. Scagnoli, B. Delley, J.J. Turner, O. Krupin, W.-S. Lee, Y.-D. Chuang,
L. Patthey, R.G. Moore, D. Lu, M. Yi, P.S. Kirchmann, M. Trigo, P. Denes, D. Doering, Z. Hussain, Z.X. Shen, D.
Prabhakaran, A.T. Boothroyd, S.L. Johnson. Phys. Rev. B 89, 220401(R) (2014).
10. Position-Momentum Duality and Fractional Quantum Hall Effect in Chern Insulators, M. Claassen, C.-H.
Lee, R. Thomale, X.-L. Qi, and T. P. Devereaux, arXiv:1502.06998, to appear in Phys. Rev. Lett. (Editor’s
Suggestion).
11. Theory of Pump-Probe Photoemission in Graphene: Ultrafast Tuning of Floquet Bands and Local
Pseudospin Textures, M. Sentef, M. Claassen, A. F. Kemper, B. Moritz, T. Oka, J. K. Freericks, and T. P.
Devereaux, arXiv:1401.5103, to appear in Nature Commun.
12. Persistent Spin Excitations in Doped Antiferromagnets Revealed by Resonant Inelastic Light Scattering, C. J.
Jia, E. A. Nowadnick, K. Wohlfeld, C.-C. Chen, S. Johnston, T. Tohyama, B. Moritz, and T. P. Devereaux, Nat.
Commun. 5, 3314 (2014).
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13. Densification process of GeO2 glass: High pressure transmission x-ray microscopy study, Y. Lin, Q. S. Zeng,
W. Yang, and W. L. Mao, Appl. Phys. Lett. 103, 261909 (2013).
14. High-pressure Raman spectroscopy of phase change materials, W. P. Hsieh, P. Zalden, M. Wuttig, A. M.
Lindenberg, and W. L. Mao, Appl. Phys. Lett. 103, 191908 (2013).
15. Evidence for photo-induced monoclinic metallic VO2 under high pressure, W.-P. Hsieh, M. Trigo, D. A.Reis,
G. Andrea Artioli, L. Malavasi, and W. L. Mao, Applied Physics Letters 104, 021917 (2014).
16. Strain derivatives of Tc in HgBa2CuO4 : The CuO2 plane alone is not enough, S. Wang, J. Zhang, J. Yan, X-J
Chen, V. V. Struzhkin, W. Tabis, N. Barisic, M. Chan, C. Dorow, X. Zhao, M. Greven, W. L. Mao, T. Geballe,
Phys. Rev. B 89, 024515 (2014).
17. High pressure Raman and X-ray diffraction study of [121] Tetramantane, F. Yang, Y. Lin, J. E. P. Dahl, R. M.
K. Carlson, W. L. Mao, J. Phys. Chem. C, doi:10.1021/jp500431 (2014).
18. Pressure induced second-order structural and electronic transition in Sr3Ir2O7, Z. Zhao, S. Wang, T. F. Qi, Q.
S. Zeng, S. Hirai, P. P. Kong, L. Li, C. Park, S. J. Yuan, C. Q. Jin, G. Cao, and W. L. Mao, J. Phys.: Condens.
Matter 26, 215402 (2014).
19. Tuning the crystal structure and electronic states of Ag2Se: Structural transitions and metallization under
pressure, Z. Zhao, S. Wang, A. Oganov, P. Chen, Z. Liu, W. L. Mao, Phys. Rev. B 89, 180102(R) (2014).
20. Universal Fractional Non-Cubic Power Law for Density of Metallic Glasses, Q. Zeng, Y. Kono, Y. Lin, Z.
Zeng, J. Wang, S. V. Sinogeikin, C. Y. Park, Y. Meng, W. Yang, H.-k. Mao, and W. L. Mao, Phys. Rev. Lett. 112,
185502 (2014).
21. Bandgap Closure and Reopening in CsAuI3 at High Pressure, Shibing Wang, Maria Baldini, Max Shapiro, Scott
Riggs, Alexander F. Kemper, Zhao Zhao, Zhenxian Liu, Thomas P. Devereaux, Ted Geballe, Ian R Fisher, and
Wendy L. Mao, Phys. Rev. B 89, 245109 (2014).
22. High-pressure storage of hydrogen fuel: ammonia borane and its related compounds, Y. Lin and W. L. Mao,
Chin. Sci. Bull. doi:10.1007/s11434-014-0624-8 (2014).
23. Deviatoric Stress-Induced Phase Transitions in Diamantane, F. Yang, Y. Lin, J. E. P. Dahl, R. M. K. Carlson,
and W. L. Mao, J. Chem. Phys. 141, 154305 (2014).
24. Pressure-Induced Conductivity and Yellow-to-Black Piezochromism in a Layered Cu–Cl Hybrid Perovskite,
A. Jaffe, Y. Lin, W. L. Mao, and H. I. Karunadasa, J. Am. Chem. Soc. 137, 1673-1678 (2015).
25. Strain-Induced Modification of Optical Selection Rules in Lanthanide-Based Upconverting Nanoparticles, M.
D. Wisser, M. Chea, Y. Lin, D. M. Wu, W. L. Mao, A. Salleo, and J. A. Dionne, Nano Lett. doi: 10.1021/nl504738k
(2015).
26. A novel phase of Li15Si4 synthesized under pressure, Z. Zeng, N. Liu, Q. F. Zeng, Q. Zhu, A. R. Oganov, Q. S.
Zeng, Y. Cui, and W. L. Mao, Adv. Energy Mat. 10.1002/aenm.201500214 (2015).
27. Magnetic excitations and phonons simultaneously studied by resonant inelastic x-ray scattering in optimally
doped Bi1.5Pb0.55Sr1.6La0.4CuO6+δ, Y. Y. Peng, M. Hashimoto, M. Moretti Sala, A. Amorese, N. B. Brookes, G.
Dellea, W.-S. Lee, M. Minola, T. Schmitt, Y. Yoshida, K.-J. Zhou, H. Eisaki, T. P. Devereaux, Z.-X. Shen, L.
Braicovich, and G. Ghiringhelli, Submitted to Phys. Rev. B.
28. Ultrafast lattice dynamics of the electronically driven, lattice directed charge density wave in TbTe3. R. G.
Moore, W. S. Lee, P. S. Kirchman, Y. D. Chuang, A. F. Kemper, M. Trigo, L. Patthey, D. H. Lu, O. Krupin, M. Yi,
D. A. Reis, D. Doering, P. Denes, W. F. Schlotter, J. J. Turner, G. Hays, P. Hering, T. Benson, J. -H. Chu, T. P.
Devereaux, I. R. Fisher, Z. Hussain, and Z. -X. Shen. Submitted to Phys. Rev. B
8
FWP#: 10017
29. Pressure induced metallization with absence of structural transition in layered MoSe2, Z. Zhao, H. Zhang, H.
Yuan, S. Wang, Y. Lin, Q. S. Zeng, Z. Liu, K. D. Patel, G. K. Solanki, Y. Cui, H. Y. Hwang, and W. L. Mao,
Nature Comm., in press.
30. Structural transition and amorphization in compressed
Hirai, Z. Zeng, and W. L. Mao, Phys. Rev. B, accepted.
-Sb2O3, Z. Zhao, Q. S. Zeng, H. Zhang, S. Wang, S.
31. Ultrafast crystallization and grain growth in shock compressed SiO2, A.E. Gleason, C. Bolme, H.J. Lee, B.
Nagler, E. Galtier, D. Milathianaki, J. Eggert, J. Hawreliak, D. Fratanduono, R. Kraus, G. Collins, W. Yang, and W.
L. Mao, Nature Comm., in review.
32. Fractal nature of atomic arrangements in metallic glass, D. Z. Chen, C.Y. Shi, Q. An, Q.S. Zeng, W. L. Mao, W.
A. Goddard, III, and J.R. Greer, Science, submitted.
33. Generalized Kitaev Models and Slave Genons, Maissam Barkeshli, Hong-Chen Jiang, Ronny Thomale, XiaoLiang Qi, Phys. Rev. Lett. 114, 026401 (2015)
34. Quantum Phase Transitions Between a Class of Symmetry Protected Topological States, Lokman Tsui, HongChen Jiang, Yuan-Ming Lu, and Dung-Hai Lee, Nuclear Physics B (2015) (In press)
35. Emergence of p+ip superconductivity in 2D strongly correlated Dirac fermions, Zheng-Cheng Gu, Hong-Chen
Jiang, G. Baskaran, arXiv:1408.6820
36. Fermionic Symmetry Protected Topological Phase Induced by Interactions, Shang-Qiang Ning, Hong-Chen
Jiang, Zheng-Xin Liu, arXiv:1412.0092
37. Charge modulation as fingerprints of phase-string triggered interference, Zheng Zhu, Chushun Tian, HongChen Jiang, Yang Qi, Zheng-Yu Weng, Jan Zaanen, arXiv:1412.3462
38. Dynamic structural response and deformations of monolayer MoS2 visualized by femtosecond electron
diffraction, Ehren M. Mannebach, Renkai Li, Karel-Alexander Duerloo, Clara Nyby, Peter Zalden, Theodore
Vecchione, Friederike Ernst, Alexander Hume Reid, Tyler Chase, Xiaozhe Shen, Stephen Weathersby, Carsten
Hast, Robert Hettel, Ryan Coffee, Nick Hartmann, Alan R. Fry, Yifei Yu, Linyou Cao, Tony Heinz, Evan J. Reed,
Hermann A. Dürr, Xijie Wang, Aaron M. Lindenberg, (Submitted), (2015)
39. MeV Ultrafast Electron Diffraction at SLAC, S. P. Weathersby, G. Brown, M. Centurion, T. F. Chase, R. Coffee,
J. Corbett, J. P. Eichner, J. C. Frisch, A. R. Fry, M. Guehr, N. Hartmann, C. Hast, R. Hettel, R. K. Jobe, E. N.
Jongewaard, J. R. Lewandowski, R. K. Li, A. M. Lindenberg, I. Makasyuk, J. E. May, D. McCormick, M. N.
Nguyen, A. H. Reid, X. Shen, K. Sokolowski-Tinten, T. Vecchione, S. L. Vetter, J. Wu, J. Yang, H. A. Durr, and X.
J. Wang, (Submitted), (2015).
40. How supercooled liquid phase-change materials crystallize: Snapshots after femtosecond optical excitation,
Peter Zalden, Alexander von Hoegen, Patrick Landreman, Matthias Wuttig, and Aaron M. Lindenberg, (Submitted),
(2015).
9
FWP#: 10017
41. Giant terahertz-driven nonlinear response in bismuth ferrite, F. Chen, J. Goodfellow, S. Liu, I. Grinberg, M. C.
Hoffmann, A.R. Damodaran, Y. Zhu, X. Zhang, I. Takeuchi, A. Rappe, L.W. Martin, H. Wen, A.M.
Lindenberg, (Submitted), (2015).
42. Visualization of nanocrystal breathing modes at extreme strains, E. Szilagyi, J.S. Wittenberg, T.A. Miller, K.
Lutker, F. Quirin, H. Lemke, D. Zhu, M. Chollet, J. Robinson, H. Wen, K. Sokolowski-Tinten, and A.M.
Lindenberg, Nat. Commun., 6, 6577 (2015)
43. Color switching with enhanced optical contrast in ultrathin phase-change materials and semiconductors
induced by femtosecond laser pulses, F.F. Schlich, P. Zalden, A.M. Lindenberg, R. Spolenak, ACS
Photonics, 2 178 (2015).
44. Ultrafast electronic and structural response of monolayer MoS2 under intense photoexcitation conditions,
E.M. Mannebach, K.N. Duerloo, L.A. Pellouchoud, M. Sher, S. Nah, Y. Kuo, Y. Yu, A. Marshall, L. Cao, E.J.
Reed, A.M. Lindenberg, ACS Nano, 8, 10734 (2014).
45. Room Temperature Stabilization of Nanoscale Superionic Ag2Se, T. Hu, J.S. Wittenberg, A.M.
Lindenberg, Nanotechnology, 25, 415705 (2014).
46. Reversible optical switching of infrared antenna resonances with ultrathin phase-change layers using
femtosecond laser pulses, Ann-Katrin U. Michel, Peter Zalden, Dmitry N. Chigrin, Matthias Wuttig, Aaron M.
Lindenberg, and Thomas Taubner, ACS Photonics, 1, 833 (2014) . Research highlight: "Phase-change control," Nat.
Photon. 8, 812 (2014).
47. Ultrafast polarization response of an optically-trapped single ferroelectric nanowire, S. Nah, Y. Kuo, F. Chen,
J. Park, R. Sinclair, A.M. Lindenberg. Nano Lett., 14, 4322 (2014).
48. Picosecond carrier recombination dynamics in chalcogen-hyperdoped silicon, M. Sher, C.B. Simmons, J.J.
Krich, A.J. Akey, M.T. Winkler, D. Recht, T. Buonassisi, M.J. Aziz, A.M. Lindenberg, Appl. Phys. Lett. 105,
053905 (2014).
49. Below gap optical absorption in GaAs driven by intense, single-cycle coherent transition radiation, J.
Goodfellow, M. Fuchs, D. Daranciang, S. Ghimire, F. Chen, H. Loos, D. Reis, A.S. Fisher, A.M. Lindenberg, Opt.
Express 22, 17423 (2014).
50. Ultrafast terahertz-induced response of GeSbTe phase-change materials, M. Shu, P. Zalden, F. Chen, B.
Weems, I. Chatzakis, F. Xiong, R. Jeyasingh, M. Hoffmann, E. Pop, H.-S.P. Wong, M. Wuttig, A.M.
Lindenberg, Appl. Phys. Lett. 104, 251907 (2014).
51. Measurement of transient atomic displacements in thin films with picosecond and femtometer resolution, M.
Kozina, T. Hu, J.S. Wittenberg, E. Szilagyi, M. Trigo, T.A. Miller, C. Uher, A. Damodaran, L. Martin, A. Mehta, J.
Corbett, J. Safranek, D.A. Reis and A.M. Lindenberg, Struct. Dyn. 1, 034301 (2014).
52. Real-time visualization of nanocrystal solid-solid transformation pathways, J.S. Wittenberg, T.A. Miller, E.
Szilagyi, K. Lutker, F. Quirin, W. Lu, H. Lemke, D. Zhu, M. Chollet, J. Robinson, H. Wen, K. Sokolowski-Tinten,
A.P. Alivisatos, A.M. Lindenberg. Nano Lett., 14, 1995 (2014).
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FWP#: 10017
53. Phonon Spectroscopy with Sub-meV Resolution by Femtosecond X-ray Diffuse Scattering, Diling Zhu,
Aymeric Robert, Tomas Henighan, Henrik T. Lemke, Matthieu Chollet, J.~Michael Glownia, David A. Reis and
Mariano Trigo, submitted to Physical Review Letters (2015).
54. Imaging transient melting of a nanocrystal using an x-ray laser,Jesse N. Clark, Loren Beitra, Gang Xiong,
David M. Fritz, Henrik T. Lemke, Diling Zhu, Matthieu Chollet, Garth J. Williams, Marc Messerschmidt, Brian
Abbey, Ross J. Harder, Alexander M. Korsunsky, Justin S. Wark, David A. Reis and Ian K. Robinson, Accepted
PNAS (2015).
55. Generation of high-frequency strain waves during femtosecond demagnetization of Fe/MgO(001) films, T.
Henighan, S. Bonetti, P. Granitzka, M. Trigo, Z. Chen, R. Kukreja, D. Higley, A. Gray, A. H. Reid, E. Jal, M.
Hoffmann, M.E. Kozina, S. Song, M. Collet, D. Zhu, J. Jeong, M. G. Samant, S. S. P. Parkin, D.A. Reis, H. A. Dürr
in preparation.
11
SIMES: Diamondoid Science and Applications
FWP#: 10018
Diamondoid Science and Applications
PIs: Nicholas A. Melosh (FWP lead), Peter R. Schreiner, Z. X. Shen
Staff Scientists: Jeremy Dahl
Postdocs and Students: Hitoshi Ishiwata, Fei Li, Natalia Fokina, Maria Gunawan, Abolfazl Hosseini, Oana
Moncea, Boryslav A. Tkachenko, Hao Yan
Overview
Diamondoids are unique new carbon-based nanomaterials consisting of 1–2 nanometer, fully hydrogen-terminated
diamond particles. Unlike their conjugated counterparts, graphene or carbon nanotubes, the carbon atoms in diamondoids
are exclusively sp3-hybridized, leading to unique electronic and mechanical properties. Diamondoids behave much like
small molecules, with atomic-level uniformity, flexible chemical functionalization, and systematic series of sizes, shapes
and chiralities. At the same time diamondoids offer more mechanical and chemical stability than small molecules, and
vastly superior size and shape control compared to inorganic nanoparticles. This family of new carbon nanomaterials is
thus an ideal platform for approaching the grand challenges of energy flow at the nanoscale and synthesis of atomically
perfect new forms of matter with better precision than any other nanomaterials system.
This program explores and develops diamondoids as a new class of functional nanomaterials based upon their unique
electronic, mechanical, and structural properties. This includes all phases of investigation, from diamondoid isolation
from petroleum, chemical functionalization, and molecular assembly, as well as electronic, optical and theoretical
characterization. We have currently focused on three areas of research: synthesis, electronic properties, and thin film
growth. This naturally requires the broad expertise and collaboration between a number of investigators to successfully
approach tackle these problems. This approach has yielded fruit, enabling synthesis of a number of new compounds, and
exploration of their structural and electronic properties. In particular the ability of these materials to control the flow of
electrons and emitted electron energy at the molecular level is an exciting direction for mastering energy flow at the
nanoscale. The team meets biweekly to review current progress and initiate new ideas.
Progress in FY2015
As planed, we prepared Se-modified diamondoids or similarly rigid molecules. Indeed, we have succeded in preparing
Se-modified diamondoids, which turned out to be rather challenging owing to the very rapid oxidation and dimerization
of the selenol end groups. We developed a novel synthetic protocol than now allows access to a large variety of
diamondoid (and other) selenols. These are now being used in in chalcogen self-assembly reactions to produce Cu and
Ag –selenolates. These materials are unusual due to their three-atom cross section backbone, and have good electronic
conductivity.
Also as proposed, we prepared completely rigid, nm-sized hydrocarbon structures are accessible through the coupling of
diamondoids through their secondary positions. Indeed, nanometer-sized doubly-bonded diamondoid dimers and trimers,
which may be viewed as models of diamond with surface sp2-defects, were prepared from their corresponding ketones
via a McMurry coupling and were characterized by spectroscopic and crystallographic methods. The neutral
hydrocarbons and their radical cations were studied utilizing density functional theory (DFT) and ab initio (MP2)
methods, which reproduce the experimental geometries and ionization potentials well. The van der Waals complexes of
the oligomers with their radical cations that are models for the self-assembly of diamondoids, form highly delocalized
and symmetric electron-deficient structures. This implies a rather high degree of -delocalization within the
hydrocarbons not too dissimilar to delocalized π-systems. As a consequence, sp2-defects are thus also expected to be
nonlocal, thereby leading to the observed high surface charge mobilities of diamond-like materials. In order to be able to
use the diamondoid oligomers for subsequent surface attachment and modification, their C–H-bond functionalizations
were studied and these provided halogen and hydroxy derivatives with conservation of unsaturation. Our studies also
help elucidate graphitization and diamond surface defects. As many properties of diamond materials can be traced back
to surface impurities, the preparation of such unsaturated larger diamondoid particles with well-defined structures can
helps interpret these findings (e.g., EAs, IPs, fluorescence etc.).
Secondly, we have developed readily accessible processes to control previously unobserved robust self-assemblies of
nanodiamonds in micro- and nanocrystals through mild vapor deposition techniques. The chemical functionalization of
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FWP#: 10018
uniform and discernible nanodiamonds was found to be a key parameter, and depending on the type of functional group
(hydroxy, fluorine, etc.) and its position on the diamondoid, the structures of the discrete deposits vary dramatically.
Thus, well-defined anisotropic structures such as rods, needles, triangles or truncated octahedra shapes were obtained,
and self-assembled structures ranging from 20 nm to several hundred micrometers formed with conservation of a similar
structure for a given diamondoid. Key thermodynamic data including sublimation enthalpy of diamondoid derivatives
are reported, and SEM of the self-assemblies coupled with EDX analyses and XRD attest for the nature and purity of
nanodiamonds crystals deposits. This attractive method is simple and outperforms in terms of deposit quality dip-coating
methods we used. This vapor phase deposition approach is expected to allow for an easy formation of diamondoid
nanoobjects on different types of substrates.
Finally, we also developed a CVD technique for growing nanoscale diamond nanoparticles from diamondoid seeds. We
investigated the critical nucleation size for diamond nucleation, and found that pentamantane, at 1.5 nm diameter and
exclusively <111> surfaces was the critical seed for nucleation. This enabled well-controlled growth of diamond that can
be further used for intentional inclusion of optically active defects.
Among developing further methods for the preparation of an even broader variety of functional diamondoid derivatives,
we will also plan the preparation of a variety of diamondoid-carbon nanotube (CNTs) adducts and / or hybrids with small
graphene models such as pyrene. These adducts will be thoroughly characterized chemically and physically (especially
I/V curves via STS) with a keen eye on single-molecule electronics and the dependence on the size, shape, attachment
geometry, and functionalization of the diamondoids.
Given the success of the self-asembly of chalcogen materials from thiol and selenol modified diamondoids we will
contrinue to explore these reactions. These materials fall into a new class of two-dimensional tessellated materials that
have been rolled up into tube- or wire like structures. Using the diamondoid thiols as a building block we will explore
which of the 3 primary and 7 secondary tessellation constructs are synthetically accessible. These may reveal new
electronic and optical properties, similar to the chemical synthetic production of graphene ribbons.
With the goal in mind of producing diamonds from diamondoids, we aim at developing further methods for the synthesis
of linear-chain diamond-like nanomaterials and diamantane polymers. The synthetic approach will primarily be based on
template reactions of dihalogen-substituted diamondoids (starting with 4,9-dihalodiamantane), using the hollow cavities
of CNTs. Under vacuum conditions, the dehalogenated intermediates spontaneously form the linear chains within the
carbon nanotubes. Transmission electron microscopy will be employed to characterize the polymers. We expect that the
present template-based approach will enable us to produce a diverse range of linear-chain polymers by choosing various
precursor molecules. This technique may offer a new strategy for the design and synthesis of one-dimensional
nanomaterials.
We will continue to pursue diamond growth using diamondoids as seed particles, and explore which defects can be
controllably introduced into different size nanoparticles. We hope to achieve N-V and Si-V centers in sub 5nm diameter
diamond particles, which have only been feasible with diamondoid seeding. We will investigate the ultimate stability
limit for these defects and measure their environmental stability and emission yield.
Finally, in the context of diamondoid van der Waals bonding situations, we will re-examine and a textbook example for a
very long C–C-bond: The reported 1.643 Å central bond length in propellane diamondoid 5-cyano-1,3dehydroadamantane, which computationally only amounts to about 1.58 Å. Hence, a re-determination could also be
used to validate various ab initio and density functional theory (DFT) approaches that do less well regarding the
inclusion of dispersion (which can be added ad hoc); we will compare these results with a series of CCSD(T)/cc-pVTZ
optimized [n.n.n]propellanes. The structure should be prepared and retermined.
One particular scientifically worthwhile challenge associated with diamondoids is their remarkable ability to stabilize
van-der-Waals contact surface through intramolecular dispersion (cf. Schreiner et al. Nature 2011, 477, 308). This
property has not been utilized, for instance in the design of novel materials and catalysts. With regard to materials, we
will attempt to prepare the hexaphenylethane (an unknown molecule) analogues with substituents in the all-meta
positions. The derivative with all-meta-tbutyl groups indeed is a stable molecule owing to the mutual London dispersion
interactions of the tbutyl groups. Diamondoid groups in the same positions should be even more favorable as the entropic
penalty (large for tbutyl substiuents) is minimized. This approach would give rise to new organic materials that can
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FWP#: 10018
dissociate at higher temperature, thereby leading to two radicals per molecule and a paramagnetic organic material
overall. There are very few examples of such materials that undoubtedly have a large variety of applications, especially
in energy science (e.g., conversion of thermal energy into magnetic moment). In the realm of catalysis, we will further
develop the use of diamondoids as sterically demanding yet dispersion energy donor binding moieties for ligands (e.g.,
mixed phospines and others). Finally, we plan on preparing large diamondoid rings connected through saturated and
unsaturated moieties for superior adhesion to nonpolar surfaces (utilizing the “Gecko”-effect).
Collaborations
Prof. Andrey A. Fokin, Kiev Polytechnic Institute, Ukraine
Prof. Jean-Cyrille Hierso, Université Burgogne, Dijon, France
Prof. Thomas Möller, Techical University of Berlin
Publications
1.
Toward an Understanding of Diamond sp2-Defects with Unsaturated Diamondoid Oligomer Models. Tatyana S.
Zhuk, Tatyana Koso, Alexander E. Pashenko, Ngo Trung Hoc, Vladimir N. Rodionov, Michael Serafin, Peter R.
Schreiner* and Andrey A Fokin* J. Am. Chem. Soc. 2015, 137, in press. DOI: 10.1021/jacs.5b01555
2.
Unconventional Molecule-Resolved Current Rectification in Diamondoid-Fullerene Hybrids. Functionalized
Nanodiamonds, part 44. Jason C. Randel, Francis C. Niestemski, Andrés R. Botello-Mendez, Warren Mar, Georges
Ndabashimiye, Sorin Melinte, Jeremy E. P. Dahl, Robert M. K. Carlson, Ekaterina D. Butova, Andrey A. Fokin,
Peter R. Schreiner, Jean-Christophe Charlier, and Hari C. Manoharan* Nature Commun. 2014, 5, 4877. DOI:
10.1038/ncomms5877. Open Access.
3.
The Functionalization of Nanodiamonds (Diamondoids) as key Parameter of the Easily Controlled Self-Assembly in
Micro- and Nanocrystals from the Vapor Phase. Functionalized Nanodiamonds, part 43. Maria A. Gunawan, Didier
Poinsot, Bruno Domenichini, Sébastien Chevalier, Céline Dirand, Andrey A. Fokin, Peter R. Schreiner,* and JeanCyrille Hierso,* Nanoscale 2015, 8, 1956–1962. DOI: 10.1039/C4NR04442H. Open Access.
4.
Selective Preparation of Diamondoid Phosphonates. Functionalized Nanodiamonds, part 44. Andrey A. Fokin,*
Raisa I. Yurchenko, Boryslav A. Tkachenko, Natalie A. Fokina, Maria A. Gunawan, Didier Poinsot, Jeremy E. P.
Dahl, Robert M. K. Carlson, Michael Serafin, Hélène Cattey, Jean-Cyrille Hierso,* and Peter R. Schreiner* J. Org.
Chem. 2014, 79, 5369–5373. DOI: 10.1021/jo500793m
5.
Functionalization of Homodiamantane: Oxygen Insertion Reactions Without Rearrangement with
Dimethyldioxirane. Functionalized Nanodiamonds, part 42. Andrey A. Fokin,* Tanya S. Zhuk, Alexander E.
Pashenko, Valeriy V. Osipov, Pavel A. Gunchenko, Michael Serafin, Peter R. Schreiner,* J. Org. Chem. 2014, 79,
1861–1866. DOI: 10.1021/jo4026594
6.
Effects of molecular structures of carbon-based molecules on bio-lubrication. Zhou, Y., et al., Carbon, 2015. 86(0):
p. 132-138.
A Novel Phase of Li15Si4 Synthesized under Pressure. Zeng, Z., et al., Advanced Energy Materials, 2015: in press
Laser-induced fluorescence of free diamondoid molecules. Richter, R., et al.,. Physical Chemistry Chemical Physics,
2015. 17(6): p. 4739-4749
7.
8.
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5
SIMES: Electronic and Magnetic Structure of Quantum Materials
FWP#: 10027
Electronic and Magnetic Structure of Quantum Materials
Principal Investigator(s): Zhi-Xun Shen, Thomas Devereaux
Staff Scientists: Makoto Hashimoto, Patrick Kirchmann, DongHui Lu, Robert Moore, Brian Moritz
Postdoctoral Scholars and Graduate Students: Sudi Chen, Yu He, Edwin Huang, Yvonne Kung, James Lee, Dominik
Leuenberger, Wei Li, Benjamin Nosarzewski, Nachum Plonka, Slavko Rebec, Elliott Rosenberg, Jonathan Sobota,
Hadas Soifer, Yao Wang, Krzysztof Wohlfeld, Shuolong Yang, Ming Yi, Jin Min Yoon, Hongyu Xiong, Chaofan
Zhang,Yan Zhang, Yi Zhang
Visiting Physicists: Lucio Braicovich, Giacomo Ghiringhelli, Rudolf Hackl, Di-Jinn Huang, Arno Kampf, Xianwen Sun,
Shujie Tang
Overview
We have made substantial progress on several research fronts to advance our understanding of complex materials
through advanced photoelectron spectroscopy techniques coupled with advanced numerical simulations. There are four
themes of complementary experimental efforts within this FWP: to study novel superconductors and related materials, to
develop in-situ materials synthesis capability, to develop time resolved photoelectron spectroscopy, and to develop spinresolved photoelectron spectroscopy, and to apply these capabilities to important contemporary material science issues.
These experiments are complemented by closely integrated theoretical simulation and investigations that study model
systems with strongly coupled degrees of freedom under equilibrium and non-equilibrium conditions. In the following,
we outline our progress through lists of bullets. As this is a brievated version, we will only highlight key results, the full
results will be included in the review document.
Progress in FY2015

Direct spectroscopic evidence for the competition between the pseudogap and superconductivity in Bi2212 cuprate
superconductors by studying the ARPES spectral weight (M. Hashimoto et al., Nature Mater 14, 37 (2015)). This
work adds one more dimension to microscopic origin for the rich physics exhibited in the cuprate phase diagram
(Invited Review: M. Hashimoto, I. M. Vishik, R.-H. He, T. P. Devereaux, Z.-X. Shen, Nature Phys 10, 483 (2014))
o Antagonistic spectral weight singularity at Tc, which is a profound signature for competition between the order
parameters for the pseudogap and superconductivity.
o Disappearance of the competition at p > 0.22 around Tc revealed by the doping dependence of the spectral
weight singularity.
o The ground state pseudogap critical point at p~0.19, which is at lower doping than p~0.22, suggesting the
reentrant behavior of the pseudogap phase boundary beneath the superconducting dome in the cuprate phase
diagram.
o Spectral weight and spectral lineshape reproduced by simulation where density wave based pseudogap,
coupling of electron to collective modes and superconductivity all contribute.
o A pathway towards more quantitative characterizations of the pseudogap order and the mode.

In-situ ARPES study of MBE grown FeSe films
o Monolayer and multilayer FeSe films have been grown and characterized in-situ by ARPES
o Robust quantum replica bands have been observed elucidating the strong, forward focused, electron-phonon
interactions between the FeSe film and underlying STO substrate. Theoretical collaborations with T.
Devereaux (SLAC), S. Johnston (U. TN) and D. H. Lee (Berkeley) have revealed how such strong e-p coupling
with dominant forward scattering can enhance Tc in all channels and is responsible for the Tc enhancement in
monolayer FeSe films (J. J. Lee et al., Nature 515, 245 (2014)).

Ex-situ studies of FeSe films
o The search for diamagnetic signature of superconductivity on capped FeSe films has revealed ferroelectric
domains that form at the interface. Domains form with the addition of Se on the surface of STO but is
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FWP#: 10027
dramatically enhanced with the addition of a monolayer of FeSe capped with Se (Y. T. Cui, et al., Phys. Rev.
Lett. 114, 037002 (2015)).

Time-resolved photoemission studies of topological insulator compounds.
o Distinguishing phonon mode energies with sub-meV separation in the time domain (J. A. Sobota
et al., Phys. Rev. Lett. 113, 157401 (2014).

Theory activities:
o Successfully obtained 10M CPU-hours in allocations for computational simulations at NERSC.
o Used quantum Monte Carlo to investigate the single-particle spectral function of the HubbardHolstein model in collaboration with S. Johnston, Tennessee, and E. A. Nowadnick, Cornell.
o Performed a combined quantum Monte Carlo and small cluster exact diagonalization study which
found no evidence for “orbital loop currents” in the cuprate pseudogap.
o Performed a “fidelity” analysis of superconductivity in extended Hubbard models for the cuprates
(arXiv).
o Investigated the signatures of a sub-dominant d-wave pairing channel in iron-based
superconductors using Raman scattering in collaboration with R. Hackl, WMI, Germany (PRX).
o Using cluster perturbation theory we have investigated the microscopic mechanisms which give
rise to the band dispersion in the Hubbard model.
o We investigated entanglement and fractionalization in one-dimensional spin-orbital system using
cluster perturbation theory and analytical techniques finding a cross-over between fractionalized
excitations and strongly entangled spin and orbital degrees of freedom as a function of orbital
splitting in collaboration with C.-C. Chen, ANL.
o Continued development of state-of-the-art charge transfer full atomic multiplet code to add
materials specificity to small cluster calculations for transition metal oxides using open-source, ab
initio back-end software sources. Developed a new algorithm, PARADISOS, which significantly
improves memory performance for small cluster exact diagonalization codes which can be used
in conjunction with the PARMETIS library and full checkerboard decomposition techniques to
treat Hilbert spaces in excess of 1010 elements.
o Continued development of state-of-the-art small cluster codes using the Krylov subspace-based
methods for efficient evaluation of wave-function time-evolution.
o Developed codes used to study the interplay between strong electronic correlations and strong
electron-phonon coupling in the Hubbard-Holstein model, examining the dynamics of a single
photo-doped hole in the Peierls phase of a one-dimensional system.

Infrastructure and equipment development
o Commission the new beamline V and related experimental end station – this facility is expected to give five
fold increase of the performance, and will substantially extend the photon energy range.
o Design and construction of sample transfer system to couple oxide MBE system, chalcogenide MBE
system and PLD system to ARPES endstation at SSRL.
o Design and construction of chalcogenide MBE system to be coupled to ARPES endstation and oxide MBE
for in-situ investigation of chalcogenide materials and chalcogenide/oxide heterostructures.
o Design, construction and testing of 4-point probe for in-situ transport measurements of thin films.
o Design and procurement of STM to couple to the MBE/ARPES system at SSRL.
o Continued development of 11eV laser in collaboration with Lumeras Inc.
o Continued development of spin-resolved ARPES system in collaboration with LBNL.
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Investigation of superconducting properties without the influence of the pseudogap in extremely overdoped
Bi2212
o Simple d-wave superconducting gap with BCS-like temperature dependence on the entire Fermi surface.
o Confirmed that this is an ideal system to study d-wave superconductivity in cuprates and identify the
bosonic mode directly related with superconductivity without the complications from the pseudogap.
Search for the re-entrant behavior of the pseudogap in the overdoped regime of the phase diagram.
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Growth of Bi2212 samples near the pseudogap critical point with precise control of the doping level.
Detailed temperature dependence study of the gap function to detect the pseudogap suppression and
disappearance in the superconducting dome.
Universal orbital-selective Mott physics in FeSe film, KFe2Se2, and Fe(Te,Se) chalcogenide systems (M. Yi et
al., Nature Communications, accepted (2015)).
Incoherent-coherent crossover and orbital dependent band renormalization in Fe(Te,Se) (Z. K. Liu et al.,
accepted by Phys. Rev. B).
Origin of the nematicity in multilayer FeSe systems (Y. Zhang et al., submitted to Nature Communications;
arXiv: 1503.01556).
MBE of oxide films
o Homoepitaxial STO films grown utilizing O-18 for investigation of isotope effect in monolayer FeSe/STO
via ARPES where preliminary results have been obtained.
o BaTiO3 and TiO2 films are being developed for investigation of the replica bands and O-18 isotope effect
in FeSe films.
o Recipes for La2CuO4, LSCO and LBCO utilizing ozone assisted MBE are under development for
exploration of electronic structure evolution with dimension and epitaxial strain via in-situ ARPES and
trARPES.
o
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Time-Resolved Photoemission studies of CDW compound CeTe3
o Momentum-dependent analysis of coherent response of amplitude and phonon modes highlights
the coupling and symmetry of charge order. (D. Leuenberger et al., Phys. Rev. B (Rapid) accepted).
Time-resolved photoemission studies of monolayer and multilayer FeSe/STO
o Substrate-induced lattice strain softens the Se A1g mode in monolayer samples and demonstrates
an abrupt phonon renormalization due to a lattice mismatch between the ultrathin film and the
substrate. (S.-L. Yang et al., Nano Lett. – under consideration)
Time-resolved Photoemission studies of optimally doped Bi2212 at high excitation densities
o Tracking a 4THz coherent phonon mode along the Fermi surface points to an electron momentum
dependent electron-phonon coupling
Time-resolved Photoemission studies of optimally doped Bi2212 at low excitation densities
o Energy-resolved hot electron population decay rates in the nodal region differ by 1-2 orders of
magnitude from single particle decay rates, suggesting that scattering channels beyond electronphonon interaction play a significant role in the electron dynamics. (S.-L. Yang et al., Phys. Rev.
Lett. – under consideration)
Theory activities:
o Continued refinement of state-of-the-art quantum Monte Carlo simulations. Multi-particle
dynamical correlation functions, optical conductivity, and Raman response in the HubbardHolstein model over a wide range of doping. Extend studies in multi-orbital models for coupling
to specific oxygen phonon modes identified in experimental studies. Investigate “cluster
geometry” effects on nematic and charge density wave response functions in multi-orbital
models.
o Develop the framework for a single simulation capable of accessing different correlation
functions such as small cluster exact diagonalization or quantum Monte Carlo for a
comprehensive view of the pseudogap.
o Provide additional phenomenological modeling to photoemission studies across the whole
cuprate phase diagram, including specific evolution of peak-dip-hump features to understand the
evolution of electron-phonon coupling with superconductivity and the pseudogap.
o Extend the modified Krylov-based exact diagonalization approach to study time evolution of
driven systems having charge, spin, orbital and lattice degrees of freedom. Continue to emphasize
driving and relaxation between distinct states of matter such as charge density wave, spin density
wave, and metallic states. Continue to investigate the possibility of “photoinduced” phase
transitions in these highly correlated systems either through charge driving (applied fields) or
direct photoexcitation.
o Further refinement of time-domain Keldysh techniques. Investigate pump-probe photoemission in
the superconducting state of d-wave superconductors and the influence of symmetry on amplitude
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mode oscillations. Continue development of codes for multi-particle response functions
appropriate for Keldysh and Krylov subspace methods for systems out of equilibrium such as
pump-probe optical conductivity, reflectivity, charge, and spin response functions. Deploy novel
non-equilibrium numerical renormalization group approach for the single-site Anderson impurity
model.
Deploy charge-transfer full atomic multiplet code. Improved usability with open-source ab initio
back-end support for transition metal oxide, chalcogenide, and pnictide materials.
Continue infrastructure development for new beamline and end station, in-situ sample preparation, time and spinresolved experiments, and STM.

Finish most of instrumentation development, focus on STM coupling and research using the new generation tools.
Collaborations
Ament, Luuk, Strategic Research at ASML, The Netherlands; Analytis, J G, UC Berkeley; Ando, Yoichi, Osaka
University; Banerjee, Tamalika, University of Groningen; Baumberger, Felix, U Geneva; Bluhm, Hendrik, Lawrence
Berkeley National Laboratory (LBNL); Cataudella, V., Universit`a di Napoli Federico II; Chen, Cheng-Chien, Argonne
National Laboratory; Chen, Yulin, Oxford University, England; Cheng, Hai-Ping, University of Florida; Chuang, Yi-De,
LBNL; Cuk, Tanja, UC Berkeley; Degiorgi, Leonardo, ETH Zurich, Switzerland; Freericks, James K., Georgetown
University; Fujimori, Atsushi, University of Tokyo, Japan; Greven, Martin, University of Minnesota; Hackl, Rudi,
Walther Meissner Institut, Bayerische Akademie der Wissenschaften, Germany; Hancock, Jason, University of
Connecticut; He, Rui-Hua, Boston College, Massachusetts; Hemminger, John C., UC Irvine; Hill, John, Brookhaven
National Laboratory; Hirschfeld, Peter, University of Florida; Hussain, Zahid, LBNL; Johnston, Steven, University of
Tennessee; Kaindl, Robert A., LBNL; Kampf, Arno P., University of Augsburg; Kemper, Alexander F., LBNL; Kim,
Changyoung, Yonsei University, South Korea; Kim, Young-June, University of Toronto, Canada; Krishnamurthy, H. R.,
Indian Institute of Science, Bangalore, India; Lee, Dung-Hai, UC Berkeley; Lipp, Magnus J.,LLNL; Liu , Amy Y.,
Georgetown University; Mazin, Igor I., Naval Research Laboratory; Meevasana, Worawat, Suranaree University of
Technology, Thailand; Mishchenko, Andrey S, RIKEN Advanced Science Institute, Japan; Monney, Claude, FritzHaber-Institut, Berlin, Germany; Nagaosa, Naoto, University of Tokyo, RIKEN Advanced Science Institute, Japan;
Nowadnick, Elizabeth A., Cornell, New York; Orenstein, Joseph, LBNL; Patthey, Luc, Paul Scherrer Institut,
Switzerland; Sawatzky, George A., University of British Columbia, Canada; Scalapino, Douglas J., UC Santa Barbara;
Scalettar, Richard T., UC Davis; Schmitt, Thorsten, Paul Scherrer Institute, Switzerland; Schoenlein, Robert W., LBNL;
Shao-Horn, Young, Massachusetts Institute of Technology; Sentef, Michael A., Max Planck Institute for the Structure
and Dynamics of Matter, Germany; Shastry, B. Sriram, UC Santa Cruz; Shen, Kyle M., Cornell University; Singh, Rajiv
R. P., UC Davis; Stock, Chris, NIST Center for Neutron Research, Indiana University Cyclotron Facility; Strocov,
Vladimir N., Paul Scherrer Institute, Switzerland; Thomale, Ronny, University of Wurzburg, Germany; Tohyama,
Takami, Kyoto University; Uchida, Shin-Ichi, University of Tokyo, Japan; van den Brink, Jeroen, IFW Dresden,
Germany; van der Marel, Dirk, Université de Genève, Switzerland; van Veenendaal, Michel, Northern Illinois
University, Argonne National Laboratory; Vernay, Francois, Université de Perpignan, France; Vishik, Inna, MIT; Yang,
WanLi, LBNL; Zaanen, Jan, University of Leiden, The Netherlands.
Publications
1. Fidelity study of superconductivity in extended Hubbard models, N. Plonka, C.J. Jia, Y. Wang, B.
Moritz, and T. P. Devereaux, arXiv:1505.01127 [cond-mat.supr-con]
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2. Amplitude mode oscillations in pump-probe photoemission spectra of electron-phonon mediated
superconductors, A. F. Kemper, M. A. Sentef, B. Moritz, J. K. Freericks, and T. P. Devereaux,
arXiv:1412.2762 [cond-mat.supr-con]
3. Direct characterization of photo-induced lattice dynamics in BaFe2As2, S. Gerber, K. W. Kim, Y.
Zhang, D. Zhu, N. Plonka, M. Yi, G. L. Dakovski, D. Leuenberger, P. S. Kirchmann, R. G. Moore, M.
Chollet, J. M. Glownia, Y. Feng, J.-S. Lee, A. Mehta, A. F. Kemper, T. Wolf, Y.-D. Chuang, Z. Hussain,
C.-C. Kao, B. Moritz, Z.-X. Shen, T. P. Devereaux, and W.-S. Lee, arXiv:1412.6842 [cond-mat.str-el]
(Accepted in Nature Communications)
4. Theory of Floquet band formation and local pseudospin textures in pump-probe photoemission of
graphene, M. A. Sentef, M. Claassen, A. F. Kemper, B. Moritz, T. Oka, J. K. Freericks, and T. P.
Devereaux, Nature Communications 6, 7047 (2015)
5. Renormalization of spectra by phase competition in the half-filled Hubbard-Holstein model, E. A.
Nowadnick, S. Johnston, B. Moritz, and T. P. Devereaux, Physical Review B 91, 165127 (2015)
6. Probing LaMO3 metal and oxygen partial density of states using x-ray emission, absorption, and
photoelectron spectroscopy, W. T. Hong, K. A. Stoerzinger, B. Moritz, T. P. Devereaux, W. Yang, and
Y. Shao-Horn, Journal of Physical Chemistry C 119, 2063-2072 (2015)
7. Direct spectroscopic evidence for phase competition between the pseudogap and
superconductivity in Bi2Sr2CaCu2O8+δ, M. Hashimoto, E. A. Nowadnick, R.-H. He, I. M. Vishik, B.
Moritz, Y. He, K. Tanaka, R. G. Moore, D.H. Lu, Y. Yoshida, M. Ishikado, T. Sasagawa, K. Fujita, S.
Ishida, S. Uchida, H. Eisaki, Z. Hussain, T. P. Devereaux, and Z.-X. Shen, Nature Materials 14, 37-42
(2015)
8. Balancing act: evidence for a strong subdominant d-wave pairing channel in Ba0.6K0.4Fe2As2, T.
Bohm, A. F. Kemper, B. Moritz, F. Kretzschmar, B. Muschler, H.-M. Eiter, R. Hackl, T. P. Devereaux, D.
J. Scalapino, and H.-H. Wen, Physical Review X 4, 041046 (2014)
9. Numerical exploration of spontaneous broken symmetries in multi-orbital Hubbard models, Y. F.
Kung, C.-C. Chen, B. Moritz, S. Johnston, R. Thomale, and T. P. Devereaux, Physical Review B 90,
224507 (2014)
10. Asymmetry of collective excitations in electron- and hole-doped cuprate superconductors, W.-S.
Lee, J. J. Lee, E. A. Nowadnick, S. Gerber, W. Tabis, S. W. Huang, V. N. Strocov, E. M. Motoyama, G.
Yu, B. Moritz, H. Y Huang, R. P. Wang, Y. B. Huang, W. B. Wu, C. T. Chen, D. J. Huang, M. Greven, T.
Schmitt, Z.-X. Shen, and T. P. Devereaux, Nature Physics 10, 883-889 (2014)
11. Effect of dynamical spectral weight redistribution on effective interactions in time-resolved
spectroscopy, A. F. Kemper, M. A. Sentef, B. Moritz, J. K. Freericks, and T. P. Devereaux, Physical
Review B 90, 075126 (2014)
12. Direct observation of bulk charge modulations in optimally-doped Bi1.5Pb0.6Sr1.54CaCu2O8+δ,
M. Hashimoto, G. Ghiringhelli, W.-S. Lee, G. Dellea, A. Amorese, C. Mazzoli, K. Kummer, N. B.
Brookes, B. Moritz, Y. Yoshida, H. Eisaki, Z. Hussain, T. P. Devereaux, Z.-X. Shen, and L. Braicovich,
Physical Review B 89, 220511(R) (2014) (Editors’ Suggestion)
13. Dynamic competition between spin density wave order and superconductivity in underdoped
Ba1−xKxFe2As2, M. Yi, Y. Zhang, Z. Liu, X. Ding, J.-H. Chu, A. F. Kemper, N. Plonka, B. Moritz, M.
Hashimoto, S.-K. Mo, Z. Hussain, T. P. Devereaux, I. R. Fisher, H.-H. Wen, Z.-X. Shen, and D.H. Lu,
Nature Communications 5, 3711 (2014)
14. Real-space visualization of remnant Mott gap and magnon excitations, Y. Wang, C.J. Jia, B. Moritz,
and T. P. Devereaux, Physical Review Letters 112, 156402 (2014)
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15. Persistent spin excitations in doped antiferromagnets revealed by resonant inelastic light
scattering, C.J. Jia, E. A. Nowadnick, K. Wohlfeld, Y. F. Kung, C.-C. Chen, S. Johnston, T. Tohyama, B.
Moritz, and T. P. Devereaux, Nature Communications 5, 3314 (2014)
16. Charge-orbital-lattice coupling effects in the dd-excitation profile of one dimensional cuprates, J. J.
Lee, B. Moritz, W.-S. Lee, M. Yi, C.J. Jia, A. P. Sorini, K. Kudo, Y. Koike, K.J. Zhou, C. Monney, V.
Strocov, L. Patthey, T. Schmitt, T. P. Devereaux, and Z.X. Shen, Physical Review B 89, 041104(R)
(2014) (Editors’ Suggestion)
17. Examining electron-boson coupling using time-resolved spectroscopy, M. Sentef, A. F. Kemper, B.
Moritz, J. K. Freericks, Z.-X. Shen, and T. P. Devereaux, Physical Review X 3, 041033 (2013)
18. Fractionalization, Entaglement, and Separation: Understanding the Collective Excitations in a SpinOrbital Chain, C.-C. Chen, M. van Veenendaal, T. P. Devereaux, K. Wohlfeld, Physical Review B 91,
165102 (2015)
19. Beyond Planck-Einstein Quanta: Amplitude driven Quantum Excitation, W. Shen, T. P. Devereaux,
and J. K. Freericks, Physical Review B 90, 195104 (2014)
20. Exact Solution for High Harmonic Generation and the Response to an AC Driving Field for a Charge
Density Wave Insulator, W. Shen, A. F. Kemper, T. P. Devereaux, and J. K. Freericks, Physical Review
B 90, 115113 (2014)
21. Exact Solution for Bloch oscillations of a Simple Charge-Density-Wave Insultor, W. Shen, T. P.
Devereaux, and J. K. Freericks, Physical Review B 89, 235129 (2014)
22. Nonequilibrium “Melting” of a Charge Density Wave Insulator via an Ultrafast Laser Pulse, W. Shen,
Y. Ge, A. Y. Liu, H. R. Krishnamurthy, T. P. Devereaux, and J. K. Freericks, Physical Review Letters 112,
176404 (2014)
23. Tunneling Spectroscopy for Probing Orbital Anisotropy in Iron Pnictides, N. Plonka, A. F. Kemper, S.
Graser, A. P. Kampf, and T. P. Devereaux, Physical Review B 88, 174518 (2013)
24. Spin chain in magnetic field: limitations of the large-N mean-field theory, K. Wohlfeld, C.-C. Chen,
M. van Veenendaal, and T. P. Devereaux, Acta Physica Polonica A 127, 201 (2015)
25. Sitewise manipulations and Mott insulator-superfluid transition of interacting photons using
superconducting circuit simulators, X.H. Deng, C.J. Jia, and C.-C. Chien, Physical Review B 91, 054515
(2015)
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Principal Investigator(s): Ian Fisher, Theodore Geballe, Aharon Kapitulnik, Steven Kivelson & Kathryn Moler
Postdoctoral Scholars and Graduate Students:, Abhimanyu Banerjee, Weejee Cho, Jiun-Haw Chu, Zheng Cui, Alan
Fang, Alex Hristov, Philip Kratz, Sam Lederer, Se Joon Lim, Min Liu, Laimei Nie, Hilary Noad, Johanna Palmstrom,
Elliott Rosenberg, Max Shapiro, Eric Spanton, Ilya Sochnikov, Christopher Watson, Patrick Worasaran, Qi Yang and
Jiecheng Zhang
Overview
The overarching goal of our research is to understand, and ultimately control, emergent behavior in strongly correlated
quantum materials. This broad class of materials holds promise for future applications directly relevant to energy
security, affecting technologies from energy distribution, to improved power electronics, to more efficient computing.
There are, however, many deep intellectual questions that need to be addressed in order to realize this potential. There
are also many opportunities for the development of novel materials with improved properties. The intellectual focus of
this FWP sits at the intersection of these challenges and opportunities. Our research combines synthesis, measurement
and theory to coherently address questions at the heart of these issues. We use cutting edge, often unique, experimental
probes to uncover novel forms of electronic order in a variety of complex materials. Our theoretical work provides a
framework to understand the rich variety of possible ordered states, and guides our ongoing measurements and synthesis
efforts. Big questions that we collectively address include; what are the rules and organizing principles governing
emergent behavior in quantum materials? What is the nature of the coexisting and competing phases in high temperature
superconductors, and how do they determine/limit the maximum critical temperature? What ordered states arise in oxide
systems with strong spin-orbit coupling, both in bulk materials and at interfaces? And finally, how does quenched
disorder affect quantum criticality and inhomogeneous electronic states in strongly correlated materials? Our research
addresses these challenging questions in the context of a range of complex quantum materials.
Progress in FY2015

Nematic component to the Hidden Order phase of URu2Si2 (Nature Communications 6, 6425 (2015).)
For materials that harbor a continuous phase transition, the susceptibility of the material to various fields can be used
to understand the nature of the fluctuating order and hence the nature of the ordered state. Here we use anisotropic
biaxial strain to probe the nematic susceptibility of URu2Si2, a heavy fermion material for which the nature of the
low temperature “hidden order“ state has defied comprehensive understanding for over 30 years. Our measurements
reveal that the fluctuating order has a nematic component, confirming reports of two-fold anisotropy in the broken
symmetry state and strongly constraining theoretical models of the hidden order phase.
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Ubiquitous signatures of nematic quantum criticality in optimally doped Fe-based superconductors
(arXiv:1503.00402)
From a theoretical perspective, recent treatments indicate that nematic fluctuations due to proximity to a nematic
quantum critical point can provide an effective pairing interaction, which, as a consequence of the q=0 nature of the
fluctuations, enhance Tc in all symmetry channels. It is therefore of considerable interest to empirically establish
whether nematic fluctuations are a characteristic feature of optimally doped high temperature superconductors. In
the present paper, we show that this appears to be the case for Fe-pnictide and chalcogenide superconductors by
considering the representative materials Ba(Fe1-xCox)2As2 & Ba(Fe1-xNix)2As2 (i.e. electron doped), Ba1-xKxFe2As2
(hole doped), BaFe2(As1-xPx)2 (isovalent substitution) and FeTe1-xSex (the optimally substituted chalcogenide
system). Furthermore, whilst the nematic susceptibility obeys a simple Curie law for optimal BaFe2(As1-xPx)2, all
other cases reveal sub-Curie behavior, which we tentatively attribute to an enhanced sensitivity to disorder in a
quantum critical regime.
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High Temperature Superconductivity in the Cuprates (Nature 518, 179 (2015).)
It is almost thirty years since the disocovery of high temperature superconductivity in the cuprates. While it is
common to start papers on this subject by bemoaning the lack of a complete understanding of the electronic
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properties of these materials, in fact there has been spectacular progress made – both theoretically and
experimentally. In this paper, the authors (a diverse group) articulate the basic – and widely accepted – theoretical
understanding of the origin of high temperature superconductivity, its relation to quantum magnetism, why it has dwave symmetry, why there is a superconducting dome, and why the phase diagram is so complicated – riddled with
“intertwined orders” of various sorts. We also carefully define the most fundamental remaining open issues in the
field – most of which have relevance much more broadly to the understanding of highly correlated electron fluids in
conditions in which the quasiparticle (Fermi liquid) paradigm is inadequate.
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Is FeSe a nematic quantum paramagnet? (arXiv:1501.00844)
It has been understood for some time how a nematic phase of the sort found in the Fe based superconductors can
arise from the thermal melting of a striped antiferromagnetic state. In this paper, we address the issue of how a zerotemperature ground-state nematic phase can arise due to the quantum melting (symmetry restoration due to quantum
fluctuations) of either a stripe or a Neel antiferromagnet. Starting from the Neel state, in particular, the nematic
phase reflects the existence of a non-trivial Berry’s phase associated with instanton (tunneling) events, which
implies as well that a quantum phase transition between these two phases would be governed by a “deconfined
quantum critical point.” We also construct an exactly solvable spin model which has a nematic quantum
paramagnetic ground-state with remarkably short-range magnetic correlations, and present evidence that this phase
arises naturally in a small but finite range of parameters in the spin-1 version of the familiar J1-J2 antiferromagnet.
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Evidence for broken time-reversal symmetry in the superconducting phase of URu2Si2 (Phys. Rev. B 91, 140506
(2015).)
Recent experimental and theoretical interest in the superconducting phase of the heavy fermion material URu2Si2
has led to a number of proposals in which the superconducting order parameter breaks time-reversal symmetry
(TRS). In this study we measured polar Kerr effect (PKE) as a function of temperature for several high-quality
single crystals of URu2Si2. We find an onset of PKE below the superconducting transition that is consistent with a
TRS-breaking order parameter. This effect appears to be independent of an additional, possibly extrinsic, PKE
generated above the hidden order transition at THO = 17.5 K, and contains structure below Tc suggestive of
additional physics within the superconducting state.
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Self Duality and a possible "Hall Insulator" phase near the Superconductor to Insulator Transition in twodimensional indium-oxide films (arXiv:1504.08115)
We combine measurements of the longitudinal and Hall resistivities of disordered two-dimensional amorphous
indium-oxide films to study the magnetic-field tuned superconductor to insulator transition (SIT) in the T→ 0 limit.
We find that the transition exhibits signatures of self-duality, and separates the superconducting state from a “Hallinsulator” phase. A higher characteristic magnetic field at which the Hall resistance is T- independent marks a
crossover to a Fermi-insulator, at which point the Hall resistivity reaches the normal-state value of H/nec. Further
conclusions are drawn using a mapping of the SIT on the quantum Hall liquid to insulator transition.
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Chiral currents and trivial edge currents in topological heterostructures (submitted to Science, and unpublished
data). We studied chiral edge currents in two systems. In one experiment, we studied ferromagnet insulator /
topological insulator heterostructures, which should host chiral edge states, although direct demonstration has been
lacking. Specifically, we used a scanning superconducting quantum interference device (SQUID) to show that
current in a magnetized EuS/Bi2Se3 heterostructure flows at the edge when the Fermi level is gate-tuned to the
surface band gap. We further induced micron-scale magnetic structures using the field coil of the SQUID. An edge
current with chirality determined by magnetization of its surrounding domain and with magnitude dependent on the
chemical potential rather than the applied current emerged at the magnetic domain boundary. Such magnetic
structures, which can be created in-situ on a TI in a designed geometry, provide a versatile platform for detecting
topological magnetoelectric effects and may enable the engineering of magnetically defined quantum bits, spinbased electronics, and topological quantum computation. In a somewhat related but so far unpublished experiment,
we studied InAs/GaSb quantum wells, widely believed to be the second experimentally demonstrated quantum spin
hall effect material. By imaging 2D current flow in InAs/GaSb quantum wells with long edges as a function of both
top gate and back gate voltages, we demonstrate the existence of edge-state-dominated conduction in a regime
believed to be trivial. In contrast, in these samples the regime believed to be topological has detectable edge states
but also substantial bulk conductivity. These results may indicate a need for caution in interpreting experiments in
quantum spin hall systems.
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Real-time and -space imaging of spontaneous magnetic fluctuations in spin ice Ho2Ti2O7 (Manuscript in
preparation). A wide variety of frustrated magnets, both classical and quantum, develop highly degenerate,
correlated ground states. In theory, quasiparticles of an exotic nature emerge above the ground state as topological
defects; in classical spin ices, these take the form of magnetic monopoles. In practice, the activation energies
determined from magnetization measurements of classical spin ices at sub Kelvin temperatures are higher than those
expected for monopole diffusion. The limits of the distributions of these energies, and therefore limits on the
relevance of the monopole picture, are not fully understood, in part because of the scarcity of experimental tools that
can directly probe monopole dynamics. Here, we use Superconducting QUantum Interference Device (SQUID)
microscopy on classical spin ice Ho2Ti2O7 to image the magnetization at the surface. We found and quantified a a
magnetization landscape that fluctuates in both time and space. The temperature, spatial, and frequency dependence
of these fluctuations reveals a narrow distribution of activation energies. This distribution is consistent with a finite
energy cost for spin flipping, or equivalently to strongly bound pairs of defects in the spin ice state rather than
‘freely’ propagating monopoles. Our technique will powerfully complement other techniques in studies of emergent
phenomena in various classical and quantum magnets by enabling real-space-, -time-, and -energy- resolved
detection of spin fluctuations.
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Elastoresistance measurements of HTSC cuprates
We have just begun a series of elastoresistance measurements of single crystals of La2-xSrxCuO4 with the aim of
investigating the evolution of the nematic susceptibility across the phase diagram in this representative cuprate
superconductor. The measurements will potentially address the origin of the HTT to LTO transition and the
presence/absence of fluctuating stripe order on the underdoped side of the phase diagram.
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Development/extension of the elastoresistance technique as a probe of broken symmetries
In collaboration with S. Raghu (another SIMES FWP), we are currently working to extend the elastoresistance
technique in order to address subtle forms of broken symmetry that might be relevant to cuprates and potentially
other strongly correlated materials. Specific ideas include use of sheer conductivity to probe broken mirror
symmetry, and a generalization of the elastoresistivity in the presence of a magnetic field.

Studies of broken time-reversal symmetry in unconventional superconductors
Our grand plan is to use Kerr effect measurements to detect signatures of time reversal symmetry breaking (TRSB)
in unconventional superconductors. Here we want to further study UPt3, which was a previous highlight from our
group, but look at the b-axis of this system. While b-axis crystals are difficult to make, our collaborators at
Northwestern succeeded in fabricating high quality crystals. In addition, we plan to study CeCoIn5, a heavy fermion
system with simple d-wave symmetry, thus, TRSB is not expected, and PrOs4Sb12 where two superconducting
transitions have been detected, but ambiguity exists with respect to TRSB of each of them.

Emergence of Metallic states near the superconductor-insulator transition for films with weak disorder
The magnetic-field tuned superconductor to insulator transition (SIT) has been studied in a variety of amorphous
2D. An important advancement in this field is that it is now accepted that in “weakly disordered” films (with normal
state resistivity small compared to the quantum of resistance, h/e2), the superconducting state gives way to an
anomalous metallic phase with a resistivity that extrapolates to a non-zero value as T → 0; this “superconductor to
metal” transition occurs at a magnetic field small compared to the mean- field Hc2. We plan to measure the Hall
effect of this phase to verify how much of a “superconducting character it possesses.

Enhanced superconducting transition temperature due to tetragonal domains in two-dimensionally doped SrTiO3
Strontium titanate is the most dilute superconductor known and is also one of the most important substrates for
growing novel superconductors. Nevertheless, the mechanism of superconductivity in strontium titanate and it
relationship to the structure and dielectric properties are not well understood. We use a scanning superconducting
quantum interference device susceptometer to image the diamagnetic response of two-dimensionally niobium-doped
SrTiO3 as a function of temperature. We find that regions of the sample, with a pattern that is characteristic of twin
domains, have a larger critical temperature, Tc, temperature than their surroundings. The observed change in critical
temperature, Tc / Tc, is of order the dielectric constant anisotropy and much larger than the tetragonal variation of
the lattice constant. These results indicate the likely importance of dielectric properties in explaining the
superconductivity, and provide a phenomenon which quantitative theories of the superconductivity must explain.
23

FWP#: 10028
Exotic phases in LBCO
In collaboration with Steve Kivelson (this FWP) and the Brookhaven group, we are studying the time and space
dependence of the magnetic landscape in LBCO.

Elastoresistance measurements of strongly correlated materials
We will continue our investigation of the elastoresistance of several families of strongly correlated materials. We will
also seek new materials that reveal electronic nematic phases, the study of which might shed light on the significance of
nematic fluctuations and nematic quantum criticality in the Fe pnictides and cuprate HTSCs.

Theory of quantum nematic phases of correlated electronic systems
We will consider our theoretical studies of the properties of quantum nematic phases in diverse examples of highly
correlated electronic systems, including quantum Hall systems, high temperature superconducting transition metal
oxides, and possibly new materials which exhibit appropriate forms of orbital ordering.

Development of all optical thermal diffusivity measurement of correlated materials
This is a new project that we are currently assessing. While such method was use in the past to study high Tc materials,
current interest in anisotropies due to charge order states suggest that this measurement can be of great importance to
detect related phase transitions. It can also be an important complementary measurement to Fisher group’s
elastoresistance measurements of strongly correlated materials.

Magnetic imaging of strongly correlated materials
We will investigate the lanscapes of magnetism, magnetic susceptibility, and magnetic fluctuations of several families of
strongly correlated materials, concentrating particularly on materials of interest to our colleagues in this FWP.
Collaborations
A. Andreev (U. of Washington); Maissam Barkeshli (UCSB); E. Bauer (LANL); L. Balicas (NHMFL); K. Behnia
(ESPCI, Paris); Christopher Bell (University of Bristol, England); E. Berg (Weizmann); G. S. Boebinger (NHMFL);
Nicholas Breznay (LBNL); V. Brouet (Universite Paris Sud, France); S. Brown (UCLA); Christoph Brüne (Wuerzburg);
S.L. Budko (Ames Laboaratory); Hartmut Buhmann (Wuerzburg); A. Carrington (Bristol, UK); A. Caldea (Oxford,
UK); P. Canfield (Ames); R. Cava (Princeton University); S. Chandan (Purdue); A. V. Chubukov (U. of Wisconsin); SB. Chung (UCLA); J. R. Cooper (Cambridge, UK); Y. Cui (Stanford University); N. Curro (UC Davis); L. DeGiorgi
(ETH Zurich, Switzerland); T. P. Devereaux (Stanford); Rui Rui Du (Rice); S. Dugdale (Bristol, UK); H. Durr (Stanford
University); C. B. Eom (Wisconsin); A. Finkelstein (Texas A&M); E. M. Forgan (Birmingham, UK); E. Fradkin
(UIUC); M. Gabay(LPS, Orsay, France); D. Goldhaber-Gordon (Stanford); S. A. Grigera (St. Andrews); R. Hackl
(WMI, Germany); W. P. Halperin (Northwestern); R-H. He (BC); J-P. Hu (Purdue); J. Hulliger (University of Berne,
Switzerland); Z. Hussain (LBL); N. Hussey (Bristol, UK); Harold Y. Hwang (Stanford University); Z. Islam (APS,
ANL); M. Jaime (NHMFL); B. Kalisky (Bar-Ilan University, Israel); A. Kaminsky (Ames Lab); A. Keles (University of
Washington), E-A. Kim (Cornell); Y-J Kim (Toronto), R. Knight (Stanford); M. Kramer (Ames Lab); T. Lemberger
(Ohio State University); D-H. Lee (UCB); A. P. M. Mackenzie (St Andrews, UK); Jochen Mannhart (Max-Planck
Stuttgart, Germany); M. B. Maple (UCSD); C. Marcus (University of Copenhagen, Denmark); Nadya Mason (Urbana);
R. McDonald (NHMFL); J. Mesot (PSI); D. Mihailovic (Lubljana, Slovenia); F. Milleto-Fabrizio (University of Naples,
Italy); L Molenkamp (Wuerzburg); J. Moodera (MIT); R. G. Moore (Stanford); J. Orenstein (LBNL); A. Palevski (Tel
Aviv University, Israel); S. Parameswaran (UCB); R. Prozorov (Ames); A. Reid (Stanford University); A. W. Rost (St.
Andrews); M. Rudner (Harvard); Andres Santander-Syro (U. of Paris, Orsay); R. Shankar (Yale); Yoni Shatner
(Wiezmann), Z-X. Shen (Stanford); K. Shih (University of Texas, Austin); B.Z. Spivak (U of Washington); S. Stemmer
(U.C.S.B.); M. Stone (Oak Ridge); M. Tanatar (Ames Laboratory); M. F. Toney (SSRL); S. Tozer (NHMFL); J.
Tranquada (BNL); Fa Wang (Peking University); K. Wang (UCLA); S.R. White (UCI); M. Wolf (Berlin, Germany); M.
Wuttig (RWTH, Aachen, Germany); Q. Xue (Tsinghua University, China); Hong Yao (Tsinghua).
24
FWP#: 10028
Publications for FY14 & FY15 (Oct 1st 2013 to date)
Oct 1st 2013 – Dec 31st 2013
1)
Evidence from tunneling spectroscopy for a quasi-one dimensional origin of superconductivity in Sr2RuO4,
I. A. Firmo, S. Lederer, C. Lupien, A. P. Mackenzie, J. C. Davis and S. A. Kivelson, Phys. Rev. B 88, 134521
(2013). (Published 28 October 2013)
2) Locally enhanced conductivity due to tetragonal domain structure in LaAlO3/SrTiO3 heterointerfaces,
Beena Kalisky , Eric Spanton, Hilary Noad , John Kirtley, Katja Nowack , Christopher Bell , Hiroki Sato ,
Masayuki Hosoda , Yanwu Xie , Yasuyuki Hikita , Carsten Woltmann , Georg Pfanzelt , Rainer Jany , Christoph
Richter , Harold Hwang , Jochen Mannhart, Kathryn Moler
Nature Materials 12, pp 1091-1095 (Published 01 December 2013).
3) Correlations and renormalization of the electron-phonon coupling in the honeycomb Hubbard ladder and
superconductivity in polyacene, G. Karakonstantakis, L. Liu, R. Thomale, and S. A. Kivelson, Phys. Rev. B 88,
224512 (2013). (Published 27 December 2013)
2014
4) Transport near a quantum critical point in BaFe2(As1-xPx)2,
James G. Analytis, H-H. Kuo, Ross D. McDonald, MarkWartenbe, P. M. C. Rourke, N. E. Hussey and I. R. Fisher,
Nature Physics 10, 194–197 (2014) [4 pages] – Published online 19 January 2014
5) Evidence of Chiral Order in the Charge-Ordered Phase of Superconducting La1.875Ba0.125CuO4 Single Crystals
Using Polar Kerr-Effect Measurements,
Hovnatan Karapetyan, Jing Xia, M. Hucker, G. D. Gu, J. M. Tranquada, M.M. Fejer, A. Kapitulnik,
Phys. Rev. Lett 112, 047003 (2014) Published 30 January 2014
6) Hysteretic behavior in the optical response of the underdoped Fe-arsenide Ba(Fe1-xCox)2As2 in the electronic
nematic phase
C. Mirri, A. Dusza, S. Bastelberger, J.-H. Chu, H.-H. Kuo, I. R. Fisher, and L. Degiorgi,
Phys. Rev. B 89, 060501(R) (2014) [5 pages] – Published 7 February 2014
7) Pulsed Laser Deposition of High-Quality Thin Films of the Insulating Ferromagnet EuS
Qi I. Yang, Jinfeng Zhao, Li Zhang, Merav Dolev, Alexander D. Fried, Ann F. Marshall, Subhash H. Risbud,
Aharon Kapitulnik, Appl. Phys. Lett. 104, 082402 (2014) (Published 25 February 2014)
8) Spectrally resolved femtosecond reflectivity relaxation dynamics in undoped spin-density wave 122-structure ironbased pnictides
A. Pogrebna, N.Vujicic, T. Mertelj, T. Borzda, G. Cao, Z. A. Xu, J.-H. Chu, I. R. Fisher, and D. Mihailovic,
Phys. Rev. B 89, 165131 (2014) [9 pages] – Published 24 April 2014
9) Dynamic competition between spin-density wave order and superconductivity in underdoped Ba1-xKxFe2As2
M. Yi, Y. Zhang, Z.-K. Liu, X. Ding, J.-H. Chu, A.F. Kemper, N. Plonka, B. Moritz, M. Hashimoto,
S.-K. Mo, Z. Hussain, T.P. Devereaux, I.R. Fisher, H.H. Wen, Z.-X. Shen & D.H. Lu,
Nature Communications DOI: 10.1038/ncomms4711 [7 pages] – Published 25 April 2014
10) Spectrally resolved femtosecond reflectivity relaxation dynamics in undoped spin-density wave 122-structure ironbased pnictides
A. Pogrebna, N.Vujicic, T. Mertelj, T. Borzda, G. Cao, Z. A. Xu, J.-H. Chu, I. R. Fisher, and D. Mihailovic,
Phys. Rev. B 89, 165131 (2014) [9 pages] – Published 24 April 2014
11) Dynamic competition between spin-density wave order and superconductivity in underdoped Ba1-xKxFe2As2
M. Yi, Y. Zhang, Z.-K. Liu, X. Ding, J.-H. Chu*, A.F. Kemper, N. Plonka, B. Moritz, M. Hashimoto,
S.-K. Mo, Z. Hussain, T.P. Devereaux, I.R. Fisher, H.H. Wen, Z.-X. Shen & D.H. Lu,
Nature Communications 5, 3711 (2014) [7 pages] DOI: 10.1038/ncomms4711 – Published 25 April 2014
25
FWP#: 10028
12) Quenched disorder and vestigial nematicity in the pseudo-gap regime of the cuprates,
L Nie, G. Tarjus, and S. A. Kivelson,
Proceedings of the National Academy of Sciences, 111, 7980-7985 (2014).(Published June 3rd 2014)
13) Effect of Disorder on the Resistivity Anisotropy Near the Electronic Nematic Phase Transition in Pure and ElectronDoped BaFe2As2
Hsueh-Hui Kuo and Ian R. Fisher,
Phys. Rev. Lett 112, 227001 (2014) [5 pages] – Published 4 June 2014
14) Observation of Broken Time-Reversal Symmetry in the B Phase of the Heavy Fermion Superconductor UPt3
E. R. Schemm, W. J. Gannon, C. Wishne, W. P. Halperin, A. Kapitulnik,
Science 345, 190-193 (2014). Published 11th July 2014.
15) Images of edge current in InAs/GaSb quantum wells
Eric M. Spanton, Katja C. Nowack, Lingjie Du, Gerald Sullivan, Rui-Rui Du, Kathryn A. Moler
Physical Review Letters, 113, 026804 (2014). Published 11 July 2014
16) Ultrafast electron dynamics in the topological insulator Bi2Se3 studied by time-resolved photoemission spectroscopy
J.A. Sobota, S.-L. Yang, D. Leuenberger, A.F. Kemper, J.G. Analytis*, I.R. Fisher, P.S. Kirchmann, T.P.
Devereaux, Z.-X. Shen,
Journal of Electron Spectroscopy and Related Phenomena 195, 249–257 (2014) [8 pages] – Published 5 Sept 2014
17) Distinguishing bulk and surface electron-phonon coupling in the topological insulator Bi2Se3 using time-resolved
photoemission spectroscopy
J. A. Sobota, S.-L. Yang, D. Leuenberger, A. F. Kemper, J. G. Analytis, I. R. Fisher, P. S. Kirchmann, T. P.
Devereaux, and Z.-X. Shen
Phys. Rev. Lett. 113, 157401 (2014) [4 pages] – Published 10 October 2014
18) Nematic-driven anisotropic electronic properties of underdoped detwinned Ba(Fe1-xCox)2As2 revealed by optical
spectroscopy
C. Mirri, A. Dusza, S. Bastelberger, J.-H. Chu*, H.-H. Kuo*, I. R. Fisher, and L. Degiorgi
Phys. Rev. B 90, 155125 (2014) [7 pages] – Published 21 October 2014
2015 (to date)
19) Erratum: Kerr effect as evidence of gyrotropic order in the cuprates [Phys. Rev. B 87, 115116 (2013)]
Pavan Hosur, A. Kapitulnik, S. A. Kivelson, J. Orenstein, S. Raghu, W. Cho, and A. Fried
Phys. Rev. B 91, 039908 – Published 26 January 2015
20) Evidence for a nematic component to the hidden-order parameter in URu2Si2 from differential elastoresistance
measurements
Scott C. Riggs, M.C. Shapiro, Akash V Maharaj, S. Raghu, E.D. Bauer, R.E. Baumbach, P. Giraldo-Gallo, Mark
Wartenbe & I.R. Fisher
Nature Communications 6, 6425 (2015) doi:10.1038/ncomms7425 [6 pages] – Published 06 March 2015
21) Wave vector dependent electron-phonon coupling drives charge-density-wave formation in TbTe3,
M. Maschek, S. Rosenkranz, R. Heid, A. H. Said, P. Giraldo-Gallo, I. R. Fisher, F. Weber
arXiv:1410.7592
22) Ubiquitous signatures of nematic quantum criticality in optimally doped Fe-based superconductors
Hsueh-Hui Kuo, Jiun-Haw Chu, Steven A. Kivelson, Ian R. Fisher
arXiv:1503.00402
23) Transfer of spectral weight across the gap of Sr2IrO4 induced by La doping
V. Brouet, J. Mansart, L. Perfetti, C. Piovera, I. Vobornik, P. Le Fèvre, F. Bertran, S. C. Riggs, M. C. Shapiro, P.
Giraldo-Gallo, I. R. Fisher,
arXiv:1503.08120
26
FWP#: 10028
24) Shearconductivity as a probe of broken mirror symmetries
Patrik Hlobil, Akash V. Maharaj, Pavan Hosur, M.C. Shapiro, I.R. Fisher, S. Raghu
arXiv:1504.05972
25) Pressure dependence of the charge-density-wave and superconducting states in GdTe3, TbTe3, and DyTe3,
D. A. Zocco, J. J. Hamlin, K. Grube, J.-H. Chu, H.-H. Kuo, I. R. Fisher, and M. B. Maple
Phys. Rev. B 91, 205114 (2015) [7 pages] – Published 14 May 2015
26) High Temperature Superconductivity in the Cuprates
B. Keimer, S. A. Kivelsin, M. Norman, S. Uchida, and J. Zaanen,
Nature 518, 179 (2015).
27) Are there quantum oscillations in an incommensurate charge density wave?
Yi Zhang, Akash V. Maharaj, and Steven A. Kivelson,
Phys. Rev. B 91, 085105 (2015).
28) Theory of Intertwined Orders in High Temperature Superconductors
Eduardo Fradkin, Steven A. Kivelsoon, and John M. Tranquada,
Reviews of Modern Physics (in press) 2015.
29) Theory of disordered unconventional superconductors
A. Keles, A. V. Andreev, S. A. Kivelson, and B.Z. Spivak,
JETP 119, 1109 (2015).
30) Is FeSe a nematic quantum paramagnet?
Fa Wang, S.A. Kivelson, and D-H. Lee,
arXiv:1501.00844.
31) Is there a hidden chiral density-wave in the iron-based superconductors?
R.M. Fernandes, S. A. Kivelson, and E. Berg,
arXiv:1504.03656.
32) Notes on Constraints for the Observation of Polar Kerr Effect in Complex Materials,
Aharon Kapitulnik,
Physica B 460, 151-158 (2015).
33) Evidence for broken time-reversal symmetry in the superconducting phase of URu2Si2,
E. R. Schemm, R. E. Baumbach, P. H. Tobash, F. Ronning, E. D. Bauer, A. Kapitulnik,
Phys. Rev. B 91, 140506 (2015).
34) Self Duality and a possible "Hall Insulator" phase near the Superconductor to Insulator Transition in twodimensional indium-oxide films,
Nicholas P. Breznay, Myles A. Steiner, Steven A. Kivelson, Aharon Kapitulnik,
arXiv:1504.08115
35) Nonsinusoidal Current-Phase Relationship in Josephson Junctions from the 3D Topological Insulator HgTe
Ilya Sochnikov, Luis Maier, Christopher A. Watson, John R. Kirtley, Charles Gould, Grigory Tkachov, Ewelina M.
Hankiewicz, Christoph Brüne, Hartmut Buhmann, Laurens W. Molenkamp, and Kathryn A. Moler,
Phys. Rev. Lett. 114, 066801 – Published 9 February 2015
27
SIMES: Spin Physics
FWP#: 10029
Spin Physics
Principal Investigator(s): David Goldhaber-Gordon, Hari Manoharan, Joeseph Orenstein, Shoucheng Zhang
Postdoctoral Scholars and Graduate Students: John Bartel, Andrew Bestwick, Derrick Boone, Eric Chatterjee, Alex
Contryman, Alex Fragapane, Alexander Hughes, Francis Niestemski, Shreyas Patankar, Jason Randel, Dominik
Rastawicki, Jing Wang, and Gang Xu
Overview
The Spin Physics program investigates novel phenomena arising from spin interactions and spin-orbit coupling in solids.
In conventional semiconductors, spin-orbit coupling gives the possibility of electric manipulation of the spin degrees of
freedom, which can be used for data storage and information processing. More recently, it is realized that spin-orbit
coupling can lead to a fundamentally new state of matter, the topological insulator. These materials have an energy gap
in the bulk, and a conducting topological state on the surface. The spin program develops theoretical concepts and
experimental tools to investigate these novel effects.
Progress in FY2015
Goldhaber-Gordon group published a paper in Physical Review Letters demonstrating a nearly ideal realization of the
quantum anomalous Hall (QAH) effect. By manipulating an unexpected magnetocaloric effect, they drove a
magnetically-doped topological insulator film to within one part per 10,000 of quantized conductance. This is an
important confirmation of topological edge transport, as predicted by Zhang and his group. Goldhaber-Gordon group is
designing new structures to manipulate magnetic domains and control the resulting conductance channels.
Goldhaber-Gordon group also developed fabrication capabilities to make back-gated HgTe/HgCdTe heterostructures,
allowing for studies of junctions between quantum Hall and quantum spin Hall edge states. In collaboration with Zhang
group, they are working toward an understanding of the interplay of different forms of topological order, specifically
how chiral edge states of quantum Hall systems equilibrate with helical edge states of quantum spin Hall systems.
Manoharan, Zhang, and Orenstein worked together on the half-metallic surface state of NaCoO2 as a platform for
topological superconductivity and Majorana fermions though the mechanism of s-wave superconductivity proximity
effect. Manoharan performed STM measurements on the surface states of NaCoO2, confirmed a bulk bandgap > 1eV,
and distinguished the p-type doping surface region expected by theory to harbor magnetic surface states. The observed
local density of states (LDOS) by STM experiments quantitatively agree with Zhang group's ab initio calculations,
indicating the single spin-polarized Fermi surface on NaCoO2. The single surface state was confirmed by ARPES
experiments done by Yulin Chen. The magnetization of the surface states was confirmed by measurements of the
magneto-optical Kerr effect by Orenstein group revealing a remnant magnetization of the state with a critical temperature
T ~ 15 K, in agreement with T-dependent scanning tunneling spectroscopy performed by Manoharan group.
Manoharan discovered a spin splitting of a 1D flatband in a linear topological defect assembled into molecular graphene,
which also becomes half-metallic at the proper doping. Manoharan and Zhang began a joint theory-experimental
investigation to explain these results. Manoharan published in Nature Communications a work on emergent current
rectification observed from diamondoids being investigated for nanoscale spin probes, and has other papers pending on
emergent granularity near superconducting-insulating transitions and the emergent half-metallic surface states.
Zhang’s group has theoretically predicted a series of new phenomena on the quantum anomalous Hall (QAH) effect in
Cr doped topological insulator (Sb,Bi)2Te3, many of which have been confirmed experimentally. In one paper, we study
the critical phenomenon of the QAH plateau transition in magnetic topological insulators. We predict that there is an
intermediate plateau with zero Hall conductance xy occurring at the coercive field, and accordingly the longitudinal
conductance xx has double peaks at the coercive field. This prediction has been confirmed by two different
experimental groups in two recent papers. In another paper, we predict the electric-field control of ferromagnetism in
thin films of insulating magnetically dopped topological insulator (Sb,Bi)2Te3. We propose that the application of an
electric field could reduce the magnetism of the thin film and therefore could induce a quantum phase transition from
ferromagnetism to paramagnetism, which has also been confirmed experimentally (private communication). Based on
this property, we further propose a topological transistor device for voltage based writing of magnetic random access
memories in magnetic tunnel junctions, which may lead to electronic applications of topological insulators.
28
SIMES: Spin Physics
FWP#: 10029
Zhang’s group has theoretically studied and predicted new materials for quantum anomalous Hall effect and quantum
spin Hall (QSH) effect in several papers. In the first paper, we propose that in ferromagnetic EuO/CdO quantum well, the
QAH effect can be realized with high Curie temperature and a larger band gap. In the second paper, we propose junction
quantum wells comprising II-VI, III-V or IV semiconductors as a large class of new materials realizing the QSH effect
and the QAH effect (with magnetic doping) with a larger band gap. In the third paper, we propose realizing the QAH
effect in more conventional diluted magnetic semiconductors with magnetically doped InAs/GaSb type-II quantum
wells. In the fourth paper, we predict that a monolayer of Cr-doped (Bi,Sb)2Te3 and GdI2 heterostructure is a quantum
anomalous Hall insulator with a band gap up to 38 meV, and the 3D quantum anomalous Hall insulator can be realized in
(Bi2/3Cr1/3)2Te3 /GdI2 superlattice.
Goldhaber-Gordon will investigate superconducting contacts to QAH systems, measuring supercurrents and magnetic
interference patterns in S-QAHE-S Josephson junctions. Goldhaber-Gordon will also use the Oersted fields from
currents in nanowires to form magnetic domain boundaries in the bulk of a magnetically-doped TI film (both Cr-BiSbTe
and the recently demonstrated V-BiSbTe, which shows QAH at up to 1 Kelvin), and test Zhang’s prediction that these
should host 1D chiral conduction channels. Orenstein will spatially map magnetic domains produced in this way. With
recently-improved clean QSH edges and nanofabrication on these systems, Goldhaber-Gordon will test Zhang’s theories
for backscattering on these edges induced by local potential perturbations.
Manoharan and Zhang plan to investigate the vortex state of the proximity coupled system of superconductor with
NaCoO2, and measure the tunneling spectrum of the core states, to observe possible signatures of the Majorana bound
state at zero energy. Together with Manoharan and Harold Hwang of MSD/SLAC, Orenstein will perform optical
measurements on systems with strong spin-orbit coupling, such as BiTeI and the interface of superconductors grown on
small gap semiconductors. Goldhaber-Gordon will perform transport measurements on these systems, particularly the
semiconducting ones.
Manoharan and Zhang will complete the theory investigation to explain experiment results on spin-polarized topological
edge states observed in molecular graphene. This will include a theoretical prediction of the conditions necessary for
half-metallicity.
Orenstein and Zhang plan to investigate the magnetic order in Cr-doped topological insulators, and study the mechanism
for ferromagnetism in the insulating regime. Together with Manoharan and Goldhaber-Gordon, Orenstein will perform
systematic magneto-optic Kerr measurements on this system. Zhang plans to perform detailed theoretical calculations on
the ferromagnetic order and Kerr rotation angle at different chemical potential and compare with the experimental data.
Goldhaber-Gordon will explore Majorana states in superconducting contacts to QAH edges. This will likely require
development of microwave-frequency conductance measurements, due to short quasiparticle relaxation times.
Manoharan will use AFM and STM/STS to investigate these lithographically patterned samples from GoldhaberGordon.
Manoharan and Zhang plan to investigate the proximity coupling between superconductors and the quantum anomalous
Hall state, and confirm the coupling by measuring the tunneling spectrum. Moreover, Manoharan and Zhang plan to
investigate the vortex state of this proximity coupled superconductor, and measure the tunneling spectrum of the core
states, to observe possible signatures of the Majorana bound state at zero energy. Goldhaber-Gordon will perform
transport measurements on these systems, in order to confirm the chiral topological superconductivity in this system.
29
SIMES: Spin Physics
FWP#: 10029
Collaborations
L. Molenkamp (Wuerzburg Germany), K. Wang (UCLA), Q-K Xue (Tsinghua, China), K.He (Tsinghua, China), ChaoXing Liu (Penn State), Rui-Rui Du (Rice), Yulin Chen (Oxford).
Publications
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Jason C. Randel, Francis C. Niestemski, Andrés R. Botello-Mendez, Warren Mar, Georges Ndabashimiye, Sorin Melinte,
Jeremy E. P. Dahl, Robert M. K. Carlson, Ekaterina D. Butova, Andrey A. Fokin, Peter R. Schreiner, Jean-Christophe
Charlier, and Hari C. Manoharan, Unconventional molecule-resolved current rectification in diamondoid-fullerene hybrids.
Nature Communications 5, 4877 (2014).
Wang, J., B. Lian, and S.-C. Zhang, Universal scaling of the quantum anomalous Hall plateau transition. Physical Review B,
2014. 89(8): p. 085106.
Wang, J., H. Mabuchi, and X.-L. Qi, Calculation of divergent photon absorption in ultrathin films of a topological insulator.
Physical Review B, 2013. 88(19): p. 195127.
Wang, J., Y. Xu, and S.-C. Zhang, Two-dimensional time-reversal-invariant topological superconductivity in a doped
quantum spin-Hall insulator. Physical Review B, 2014. 90(5): p. 054503.
Wang, Z. and S.-C. Zhang, Topological Invariants and Ground-State Wave functions of Topological Insulators on a Torus.
Physical Review X, 2014. 4(1): p. 011006.
Yuan, H., et al., Generation and electric control of spin-valley-coupled circular photogalvanic current in WSe2. Nat Nano,
2014. advance online publication.
Yuan, H., et al., Generation and electric control of spin–valley-coupled circular photogalvanic current in WSe2. Nat Nano,
2014. 9(10): p. 851-857.
Zhang, H., et al., Topological States in Ferromagnetic CdO/EuO Superlattices and Quantum Wells. Physical Review Letters,
2014. 112(9): p. 096804.
Zhang, H., et al., Quantum Spin Hall and Quantum Anomalous Hall States Realized in Junction Quantum Wells. Physical
Review Letters, 2014. 112(21): p. 216803.
A.J. Bestwick, E.J. Fox, Xufeng Kou, Lei Pan, Kang L. Wang, D. Goldhaber-Gordon, Precise Quantization of the
Anomalous Hall Effect near Zero Magnetic Field. Physical Review Letters 114, 187201 (2015).
Eric Yue Ma, M. Reyes Calvo, Jing Wang, Biao Lian, Mathias Mühlbauer, Christoph Brüne, Yong-Tao Cui, Keji Lai,
Worasom Kundhikanjana, Yongliang Yang, Matthias Baenninger, Markus König, Christopher Ames, Hartmut Buhmann,
Philipp Leubner, Laurens W. Molenkamp, Shou-Cheng Zhang, David Goldhaber-Gordon, Michael K. Kelly, and Zhi-Xun
Shen. To be published in Nature Communications. [Primary ownership is in another FWP, but Zhang and Goldhaber-Gordon,
together with our group members supported on DOE, participated in key ways].
Shreyas Patankar, J. P. Hinton, Joel Griesmar, J. Orenstein, J. S. Dodge, Xufeng Kou, Lei Pan, Kang L. Wang, A. J.
Bestwick, E. J. Fox, D. Goldhaber-Gordon, Jing Wang, Shou-Cheng Zhang, Resonant magneto-optic Kerr effect in the
magnetic topological insulator Cr:(Sbx,Bi1-x)2Te3, arXiv:1505.00728.
P. Giraldo-Gallo, Y. Zhang, C. Parra, H. C. Manoharan, M. R. Beasley, T. H. Geballe, M. J. Kramer, I. R. Fisher, Stripe-like
nanoscale structural phase separation and optimal inhomogeneity in superconducting BaPb1−xBixO3. Nature
Communications, in review (2015). arXiv:1407.7611.
30
SIMES: Clathrin Biotemplating
FWP#: 10031
Clathrin Biotemplating
Principal Investigators: Sarah Heilshorn, Sebastian Doniach, Nicholas Melosh, Andrew Spakowitz
Postdoctoral Scholars and Graduate Students: Nicholas Cordella, Abbygail Foster, Brad Krajina, Yifan
Kong, Derek Mendez, Kevin Martinez Raines, and Gundolf Schenk
Overview
The focus of this multi-disciplinary research program is to characterize and exploit the tailored molecular
interactions inherent in biological systems. Such understanding will enable engineering of responsive,
biomimetic materials that exhibit self-healing and self-regulating transformations. These materials will lead to
fundamentally new designs in biomimetic organic/inorganic devices for energy storage, catalysis, solar cells,
and fuel cells. The team integrates a wide range of experimental and theoretical approaches to assemble,
characterize, and model dynamic assembly. Our recent collaborative effort has focused on experimental and
theoretical insights into the fundamentals of biomimetic self-assembly in two and three dimensions, including
the development of an Artificial Clathrin Mimetic system that exhibits many of the properties and behaviors
of natural clathrin. Furthermore, we are investigating the effects of local topological transformations on the
structure and dynamics of supercoiled DNA in order to develop a DNA-based system with novel nanoscale
behavior that can assemble responsive materials. Our team is developing novel synthesis and characterization
strategies to enable the creation and analysis of our biomimetic materials, including the development of
advanced x-ray characterization techniques for atomic scale resolution of biomaterials with local order but
disorder at large length scales.
Progress in FY2015
Our FWP has built a platform system that can leverage the insights learned from the clathrin system, but with
more control over geometry and more amenable to fabrication of larger yields. In particular, we have created
“Artificial Clathrin Mimetics” (ACMs) out of thin metal structures with several of the characteristics of
clathrin (3-armed legs, localized binding sites, propensity to attach to 2D interfaces) in order to reproduce the
dynamic assembly and sampling behavior of native clathrin. By
selective functionalization of the ACM faces, we can order them
onto fluid 2D air-water interfaces and manipulate their selfassembly structurally and chemically. These particles have been
fabricated as micron-sized structural analogues of clathrin, with
their self-assembling behavior visualized by optical microscopy
at liquid-air interfaces. This general class of behaviors could
recreate one of the most advanced and dynamic processes in
biology, and would open up an entirely new, micron scale
sampling and assembly method.
Theoretical efforts in the project have developed a
predictive theoretical model for the structure and dynamics of
clathrin to establish responsive nanoscale assemblies. Our
modeling of clathrin structural transformations led to new insight
into the pivotal role of topological transformations within protein
networks in dictating large-scale structural transitions. Our
recent work in modeling the bud formation in clathrin was
featured on the cover the Soft Matter in January 2015 (see
Figure 1). To complement our work on clathrin, we are currently
Figure 1: Cover image of our theoretical
developing a DNA-based system that utilizes local topological
model of clathrin bud formation on a
changes to trigger structural transformations. This system will be
membrane.
used to create novel structures at the nanoscale, and
incorporating such structures into 2D membranes and 3D gels will result in materials that exhibit large-scale
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FWP#: 10031
structural changes in response to local dynamic transformations. Double-stranded DNA behavior is strongly
influenced by two topological contributions: twist-induced supercoiling and knotting. We have developed a
new approach to modeling proteins and nucleic acids that permits us to predict behavior over a range of
length and time scales that were previously inaccessible. Furthermore, our new model permits the efficient
evaluation of topological quantities associated with supercoiling and knotting. Our theoretical model shows
good agreement with the measured structure of supercoiled DNA from dynamic light scattering, and we are
currently preparing a manuscript that elucidates the progression of structural transformations in supercoiled
DNA.
This FWP has developed theoretical and computational models for clathrin proteins and DNA, both
exhibiting complex self-assembly and topological effects in their individual and collective behavior. These
models will be combined to establish a predictive model for a biomimetic clathrin system that spontaneously
assembles on a bilayer or interface. One of the most exciting goals for the next year is fully recreating the
endocytosis ‘sampling’ of extracellular contents that clathrin normally performs in the cell. This would create
truly advanced biomimetic behavior that could eventually be leveraged for continuous fluidic monitoring,
non-destructive single-cell sampling, and self-healing structures. By changing the shape and functionalization
of the ACM particles, we aim to mechanically control the underlying lipid support in a similar way to
clathrin. We also aim to use the surface properties of these particles to localize secondary, non-membraneinteracting structures to the membrane-assembling particles. These secondary self-assembled structures would
allow us to add additional functionality to the clathrin mimicking particles, and recreate the interesting
biophysical functionality. Our efforts in modeling correlated X-ray scattering (CXS) will be used to determine
dynamic DNA structural properties ranging from 1 to 100 nanometers. Models are currently being compared
with experimental data sets obtained at the free-electron laser at SACLA (Japan). These efforts will be used as
a structural characterization of supercoiled DNA, which will aid in the development of DNA-based,
responsive materials that utilize local topological changes to elicit large-scale structural changes.
We plan to study the effects of topoisomerases on the conformations of DNA plasmids using CXS. This will
provide a direct measure of the degree of supercoiling of the DNA as a function of the degree of winding of
the DNA by various topoisomerases. We have performed simulations of the CXS expected from DNA and
expect to use these as a template for analysis of experimental data acquired in the coming 1-2 yeas. These
data will inform our design of a DNA-based material composed of interconnected rings of DNA. Introducing
local topological changes of the DNA supercoiling will result in large-scale changes in material shape and
rheological properties. SIMES will undergo its triannual DOE program review November 2015. A full
narrative of the SIMES FWP program will be available at that time.
Collaborations
Gyan Bhanot (Rutgers University), Marc Delarue (Institute Pasteur, Paris, France), Henri Orland (CEA,
Saclay, France), Alberto Salleo (Stanford University), Jay Schieber (Illinois Institute of Technology), Soichi
Wakatsuke (SLAC and Stanford Med School), Peter Zwart (LBNL)
Publications
Peer-Reviewed Journal Articles - Full DOE Support
1. J. J. VanDersarl, S. Mehraeen, A. P. Schoen, S. C. Heilshorn, A. J. Spakowitz, N. A. Melosh. "Rheology
and simulation of 2-dimensional clathrin protein network assembly." Soft Matter, 2014, 10(33): 62196227.
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2. N. Cordella, T. J. Lampo, S. Mehraeen, A. J. Spakowitz. "Membrane Fluctuations Destabilize Clathrin
Protein Lattice Order." Biophysical Journal, 2014, 106(7): 1476-1488.
3. K. N. L. Huggins, A. P. Schoen, M. A. Arunagirinathan, S. C. Heilshorn. "Multi-site functionalization of
protein scaffolds for bimetallic nanoparticle templating." Advanced Functional Materials, 2014, 24(48):
7737–7744.
4. N. Cordella, T. Lampo, N. Melosh, A. J. Spakowitz. "Membrane indentation triggers clathrin lattice
reorganization and fluidization." Soft Matter, 2015, 11(3): 439-448.
Peer-Reviewed Journal Articles - Partial DOE Support
5.
D. Mendez, T. J. Lane, J. Sung, J. Sellberg, C. Levard, H. Watkins, A. E. Cohen, M. Soltis, S. Sutton, J.
Spudich, V. Pande, D. Ratner, S. Doniach. “Observation of correlated X-ray scattering at atomic
resolution.” Phil. Trans. R. Soc. B 2014 369, 20130315, published 9 June 2014.
This FWP provided support for data acquisition and analysis by PhD student, Derek Mendez.
33
SIMES: Magnetization & Dynamics
FWP#: 10067
Magnetization & Dynamics
Principal Investigator(s): Hermann Dürr, Katheryn Moler, Joachim Stöhr
Staff Scientists: Matthias Hoffmann, John Kirtley, and Alexander Reid
Postdoctoral Scholars and Graduate Students: Tyler Chase, Zhao Chen, Patrick Granitzka, Daniel Higley, Konstantin
Hirsch, Emmanuelle Jal, TianMin Liu, and Yihua Wang
Visiting Scientist: Patrick Granitzka
Overview
The FWP aims at developing a world leading program to understand and control the nanoscale dynamics of complex
magnetic materials using soft x-rays at the Linac Coherent Light Source (LCLS) and the Stanford Synchrotron Radiation
Laboratory (SSRL). These activities are complemented by laser and electron beam based studies using intense THz
pulses to control spin and charge motion in materials. The program addresses the grand challenge problems of
emergence of mesoscale spin & charge order far (or even very far) from equilibrium with the specific goal of impacting
information technology, a key area underlying US competitiveness and scientific and technological advances in our
modern data centric world. The research thrusts in the FWP focus at developing a microscopic understanding of (1) alloptical magnetic switching in metallic alloys, and (2) electric field driven metal-insulator transitions in strongly
correlated materials. (3) It also aims at developing a new generation of non-linear x-ray techniques such as stimulated
inelastic x-ray scattering to uniquely probe the electronic and spin interactions in emergent mesoscopic phases.
Progress in FY2015
Significant progress has been achieved in all three research thrusts through successful experiments at SSRL, LCLS and
other FEL sources. In the following, we outline our progress:

We used laser-based THz radiation to drive spin dynamics in a prototypical ferrimagnet DyFeO to prepare for future
LCLS beamtime applications [1].

In collaboration with external groups we performed x-ray imaging of Co nanoislands [2] and studied dynamical
properties of stripe domain ordering [3].

Using SSRL beamline 13, we have investigated the magnetic domain sizes for the latest generation of magnetic hard
disc drives with elastic resonant magnetic scattering. These investigations performed in close collaboration with
Hitach (HGST) provide valuable input for tailoring future device generations [4].

We have continued our investigatigation of the insulator-metal transition in strongly correlated oxides.
o Using Resonant Inelastic X-ray Scattering (RIXS) at the Swiss Light Source (SLS) we probed the evolution
of the electronic excitations across the metal-insulator transition in VO2. In collaboration with theory
groups data analysis is currently in progress.
o We has performed x-ray spectroscopy of the VO2 insulator-metal transition in thermal equilibrium at ALS
revealing that electron correlations are the main driving [5].
o We performed optical pump-probe spectroscopy measuremnts in collaboration with F. Parmigiani to
investigate the insulator-metal transition in magnetite [6]

In collaboration with M. Guehr, we used VUV radiation form laboratory based high-harmonic sources to study
transient gratings generated by optically pumping VO2 across the insulator-metal transition [7-9].

Nonlinear x-ray phenomena relatd to the creation of x-ray transparency of matter by stimulated scattering was
investigated theoretically [10]. This provides the basis for the ongoing analysis of LCLS experiemtnts aimed at
demonstrating these effects experimentally.

We have investigated the magnetic domain sizes written by fs laser illumination of FeCoTb alloys. Such materials
display all-optical magnetization reversal. The goal of these studies is to use high-anisotropy for writing nanoscale
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magnetic domains (‘bits’). The experiments demonstrate that ‘bit’ magnetization can be deterministically reversed
by single optical laser pusles [11]. These experiemtns lead the way towards imaging the magnetization reversal
during all-optical switching in real time. A beamtime at LCLS towards this goal has been granted in FY2015. Data
analysis will extend into FY2016.

Using the SSRL beamline 13, we have demonstrated high-resolution imaging of
o Transient spin accumulation in non-magnetic Cu layers when current is passed through an adjacent
ferromagnetic Co layer [12]. This study opens the dor for direct imaging of spin transport in spintronics
which will be one of the focal point in this FWP in 2016 and beyond.
o Non-linear magnetic solitons excited via spin transfer torque effects in the vicinity of a magnetic
nanocontact [13]. This is the first time that such spin wave excitations have been observed directly and
opens up a new field of exploration.
o These activities were enabled by systematically imporving the experiemtnal infrastructure at beamine 13 in
close collaboration with the beamline scientist (H. Ohldag) [14].

Using the XPP station at LCLS we strated to investigate the so-far unexplored ultrafast lattice dynamics during fs
laser heating of ferromagnetic materials. In close collaboration with D. Reis (FWP#`10017/Devereaux) we found
coherent strain wave propagation though 20nm Fe flims grown epitaxially onto MgO substrates. The high frequency
(up to 3.5THz) is surprising and points towards a required extension of current models of ultrafast electron phonon
coupling [15].
We started using fs electron pulses as complementray frobes to hard x-rays from LCLS as probes of lattice dynamics
[16]. Commissioning a new ultrafsst electron scattering experiment at SLAC (operated by the SLAC accelerator
division, X. Wang) we collaborated with A. Lindenberg (FWP#10017/Devereaux) on first studies on ultrafast lattice
dynamics in2D materials [18].

Following the program renewal in 2015 the FWP will continue the successful activities described above. In addition
more focus will be put (in collaboration with D. Reis) to the use of hard x-rays from LCLS to also probe ultrafast phonon
excitations during fs laser heating of magnetic materials. This will be strengthened by including the use of
complementary ultrafast electron scattering probes (developed and operated within the SLAC accelerator division, lead:
X. Wang). It is suggested to do this in a cost neutral way by curtailing present activities using laboratory-based magnetic
imaging techniques (K. Moler).
The research thrusts in the FWP will continue to build on the successful FY2015 efforts and will include further
scientific challenges identified at a 2015 DOE DMSE workshop on “Static and Dynamic Interface Effects in
Magnetism”. In FY 2016 and beyond our goals are to develop a microscopic understanding of (1) all-optical magnetic
switching in metallic alloys and heterostructures, and (2) the current-driven spin dynamics at magnetic interfaces. We
finally aim at addressing the question (3) How is angular momentum conserved far from equilibrium? We will use soft
x-rays form LCLS and SSRL to address (1) and (2). (3) will be addressed using the emerging ultrafast x-ray and electron
scattering probes of lattice dynamics. This should allow us to finally address a question at the heart of ultrafast
magnetism that has remained unanswered since its inception 20 years ago.
Activities at LCLS aiming at all-optical magnetic switching will continue and we will increasingly use electron
diffraction as a complementary tool compared to hard x-rays from LCLS. We will use higher spatial resoliution
becoming available at SSRL for spin transport studies. Synchrotron and laser based charaterization of new materials and
nanostructures will continue hopefully culminating in further high-profile applications for LCLS beamtime.
Collaborations
Bert Hecht (Wuerzburg Germany), Theo Rasing (Radboud University Nijmegen, NL), Mark Golden (University of
Amsterdam, NL), Andy Kent (Columbia University), Stuart Parkin (IBM Almaden), Olav Hellwig (HGST), Keith
Nelson (MIT), Rick Averitt (Boston Univiersity), Heidan Wen, John Freeland (APS, Argonne Nat. Lab.), Christian
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FWP#: 10067
Schüssler-Langeheine (HZ Berlin, Germany, A. Scherz (XFEL, Germany), C. Back (U. Regensburg, Germany), E.
Fullerton (UCSD), F. Parmigiani (Trieste, Italy).
Publications
1.
Terahertz-driven magnetism dynamics in DyFeO3, A. H. M. Reid, A. V. Kimel, Th. Rasing, R. V. Pisarev, H. A.
Dürr, M. C. Hoffmann, Appl. Phys. Lett. 106, 082403 (2015).
2.
Spin reorientation and large magnetic anisotropy of metastable body-centered-cubic Co islands on Au(001),
T. Miyamachi, T. Kawagoe, S. Imada, M. Tsunekawa, H. Fujiwara, M. Geshi, A. Sekiyama, K. Fukumoto, F. H.
Chang, H. J. Lin, F. Kronast, H. Dürr, C. T. Chen, S. Suga, Phys. Rev. B 90, 174410 (2014).
3.
Irreversible transformation of ferromagnetic ordered stripe domains in single-shot infrared-pump/resonantx-ray-scattering-probe experiments, Nicolas Bergeard, Stefan Schaffert, Victor Lopez-Flores, Nicolas Jaouen, Jan
Geilhufe, Christian M. Günther, Michael Schneider, Catherine Graves, Tianhan Wang, Benny Wu, Andreas Scherz,
Cedric Baumier, Renaud Delaunay, Franck Fortuna, Marina Tortarolo, Bharati Tudu, Oleg Krupin, Michael P.
Minitti, Joe Robinson, William F. Schlotter, Joshua J. Turner, Jan Lüning, Stefan Eisebitt, Christine Boeglin,
Phys. Rev. B 91, 054416 (2015) .
4.
Extracting magnetic cluster size and its distributions in advanced perpendicular recording media with
shrinking grain size using small angle x-ray scattering, Virat Mehta, Tianhan Wang, Yoshihiro Ikeda, Ken
Takano, Bruce D. Terris, Benny Wu, Catherine Graves, Hermann A. Dürr, Andreas Scherz, Jo Stöhr and Olav
Hellwig, App. Phys. Lett. 106, 202403 (2015).
5.
Correlation-driven insulator-metal transition in near-ideal vanadium dioxide films, A. X. Gray, J. Jeong, N. P.
Aetukuri, P. Granitzka, Z. Chen, R. Kukreja, D. Higley, T. Chase, A. H. Reid, H. Ohldag, M. Marcus, A. Scholl, A.
T. Young, A. Doran, C. A. Jenkins, P. Shafer, E. Arenholz, M. G. Samant, S. S. P. Parkin, H. A. Dürr, Phys. Rev.
Lett. submitted (2015) arXiv:1503.07892
6.
Signature of the phase separation in the non-equilibrium Verwey transition in magnetite, F. Randi, I. Vergara
Kausel, F. Novelli, M. Esposito, M. Dell’Angela, C. Schüßler-Langeheine, P. Metcalf, R. Kukreja, H. Dürr, M.
Grüninger, D. Fausti, F. Parmigiani, Phys. Rev. B submitted (2015).
7.
Broadband extreme ultraviolet probing of transient gratings in vanadium dioxide, Emily Sistrunk, Jakob Grilj,
Jaewoo Jeong, Mahesh G. Samant, Alexander X. Gray, Hermann A. Dürr, Stuart S. P. Parkin, Markus Gühr, Optics
Express 23, 4340 (2015).
8.
Extreme Ultraviolet Transient Grating Measurement of Insulator-Metal Transition Dynamics in VO2, Emily
Sistrunk, Jakob Grilj, Jaewoo Jeong, Mahesh G. Samant, Alexander X. Gray, Hermann A. Dürr, Stuart S. P. Parkin,
Markus Gühr, Ultrafast Phenomena XIX, Springer Proceedings in Physics Volume 162, 64 (2015).
9.
Self referencing heterodyne transient grating spectroscopy with short wavelength, Jakob Grilj, Emily Sistrunk,
Jaewoo Jeong, Mahesh G. Samant, Alexander X. Gray, Hermann A. Dürr, Stuart S. P. Parkin, Markus Gühr,
Photonics 2, 392-401 (2015).
10. Creation of X-Ray Transparency of Matter by Stimulated Elastic Forward Scattering, J. Stöhr, A. Scherz,
Phys. Rev. Lett. submitted (2015).
11. Nanoscale confinement of all-optical magnetic switching in TbFeCo – competition with nanoscale
heterogeneity, TianMin Liu, Tianhan Wang, Alexander H. Reid, Matteo Savoini, Xiaofei Wu, Benny Koene,
Patrick Granitzka, Catherine Graves, Daniel Higley, Zhao Chen, Gary Razinskas, Markus Hantschmann, Andreas
Scherz, Joachim Stöhr, Arata Tsukamoto, Bert Hecht, Alexey V. Kimel, Andrei Kirilyuk, Theo Rasing, Hermann A.
Dürr, submitted (2015) arXiv:1409.1280.
12. X-Ray Detection of Transient Spin Accumulation on Cu atoms near a Co/Cu Interface, R. Kukreja, S. Bonetti,
Z. Chen, D. Backes, Y. Acremann, J. Katine, A.D. Kent, H. A. Dürr, H. Ohldag, J. Stöhr, Phys. Rev. Lett.
submitted (2015) arXiv:1503.07275.
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FWP#: 10067
13. Direct observation and imaging of a spin-wave soliton with p−like symmetry, S. Bonetti, R. Kukreja, Z. Chen,
F. Macia, J. M. Hernandez, A. Eklund, D. Backes, J. Frisch, J. Katine, G. Malm, S. Urazhdin, A. D. Kent, J. Stöhr,
H. Ohldag, H. A. Dürr, submitted (2015) arXiv:1504.00144.
14. Microwave soft x-ray microscopy for nanoscale magnetization dynamics in the 5–10 GHz frequency range,
Stefano Bonetti, Roopali Kukreja, Zhao Chen, Detlef Spoddig, Katharina Ollefs, Christian Schöppner, Ralf
Meckenstock, Andreas Ney, Jude Pinto, Richard Houanche, Josef Frisch, Joachim Stöhr, Hermann Dürr, Hendrik
Ohldag, submitted (2015) arXiv:1504.07561.
15. Generation of high-frequency strain waves during femtosecond demagnetization of Fe/MgO(001) films, T.
Henighan, S. Bonetti, P. Granitzka, M. Trigo, Z. Chen, R. Kukreja, D. Higley, A. Gray, A. H. Reid, E. Jal, M.
Hoffmann, M.E. Kozina, S. Song, M. Collet, D. Zhu, J. Jeong, M. G. Samant, S. S. P. Parkin, D.A. Reis, H. A. Dürr,
in preparation (2015).
16. The future of electron microscopy, Yimei Zhu, Hermann Dürr, Physics Today 68, 32 (2015).
17. MeV Ultrafast Electron Diffraction at SLAC, S. P. Weathersby, G. Brown, M. Centurion, T. F. Chase, R. Coffee,
J. Corbett, J. P. Eichner, J. C. Frisch, A. R. Fry, M. Gühr, N. Hartmann, C. Hast, R. Hettel, R. K. Jobe, E. N.
Jongewaard, J. R. Lewandowski, R. K. Li, A. M. Lindenberg, I. Makasyuk, J. E. May, D. McCormick, M. N.
Nguyen, A. H. Reid, X. Shen, K. Sokolowski-Tinten, T. Vecchione, S. L. Vetter, J. Wu, J. Yang, H. A. Dürr, X. J.
Wang, submitted (2015).
18. Dynamic structural response and deformations of monolayer MoS2 visualized by femtosecond electron
Diffraction, Ehren M. Mannebach, Renkai Li, Karel-Alexander Duerloo, Clara Nyby, Peter Zalden, Theodore
Vecchione, Friederike Ernst, Alexander Hume Reid, Tyler Chase, Xiaozhe Shen, Stephen Weathersby, Carsten
Hast, Robert Hettel, Ryan Coffee, Nick Hartmann, Alan R. Fry, Yifei Yu, Linyou Cao, Tony Heinz, Evan J. Reed,
Hermann A. Dürr, Xijie Wang, Aaron M. Lindenberg, submitted (2015).
37
SIMES: Atomic Engineering Oxide Heterostructures: Materials by Design
FWP#: 10069
Atomic Engineering Oxide Heterostructures:
Materials by Design
Principal Investigator(s): Harold Y. Hwang (FWP lead), Srinivas Raghu, Yasuyuki Hikita
Staff Scientists: Jun-Sik Lee, Yanwu Xie, Hongtao Yuan
Postdoctoral Scholars and Graduate Students: Zhuoyu Chen, Samuel Crossley, Yaron Gross, Seung Sae Hong, Pavan
Hosur, Hisashi Inoue, Rea Kolbl, Di Lu, Akash Maharaj, Tyler Merz, Kazunori Nishio, and Hyeok Yoon
Visiting Physicists: Takashi Tachikawa
Overview
The overarching scientific goals of this FWP are to use techniques we have developed for atomic-scale synthesis of
complex oxide heterostructures to address the grand challenges for basic energy sciences. The issues we investigate are
central to the challenge of “how do we atomically design and perfect revolutionary new forms of matter with tailored
properties”, and which are also important to the challenges of controlling processes at the electron level, understanding
and creating emergent phenomena, and mastering energy and information on the nanoscale. Keywords for this FWP are
emergence, design, and engineering:

Emergence – how can we harness the strongly interacting charge, spin, orbital, and lattice degrees of freedom of
transition metal oxides to create new states at their surfaces and interfaces, which exhibit properties beyond their
bulk constituents?

Design – how can we use theory to transcend intuition and serendipity, and move towards the rational construction
of materials at the atomic scale?

Engineering – how can we use the flexibility and reduced symmetry of oxide interfaces and surfaces to enhance
their properties and band lineups for optimal use in energy technologies?
X-ray scattering, spectroscopy, and microscopy are used to examine the surface and interface electronic structure, their
nanoscale coupling, and their lateral nanoscale static and dynamic order. Magnetotransport and scanning probes are used
to study artificial two-dimensional (2D) superconducting and magnetic oxide heterostructures, towards the development
of the mesoscopic physics of d-electron systems. Advanced analytical and computational theory techniques are applied
to develop a quantitative foundation for analysis and predictive design. In addition to the core mission of DoE BES,
these aims are well aligned to the Materials Genome Initiative, and the Mesoscale Materials and Chemistry Initiative
currently being developed.
Progress in FY2015

We have suggested a set of transport measurements that can be used to detect spontaneous mirror symmetry
breaking in correlated electron materials. The idea is to measure longitudinal resistivity in the presence of shear
strain, or to measure the Hall resistivity in the presence of uniaxial strain. Neither response is finite when certain
mirror planes are present in the system. We suggested that several candidate phases for the pseudogap regime of
hole-doped cuprate materials would exhibit a finite value of such response functions and made concrete estimates
for several distinct experimental protocols.

We have studied quantum oscillations signatures of charge ordering in cuprate superconductors. We are in the
process of studying quantum oscillations in oxide interfaces to deduce the form and magnitude of spin-orbit
coupling present in these interfaces.

We have developed dual gate structures which can independently modulate the mobility and carrier density in
superconducting oxide heterointerfaces, using a hybrid ionic-liquid/solid gate technique.

We have constructed a simple theory for the non-monotonic variation of Tc as a function of electron concentration
in 3D strontium titanate. The theory invokes the proximity to the BEC-BCS crossover. We are currently contrasting
the results for the 3D bulk and the 2D interfaces in comparison with experiments.
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FWP#: 10069

We are considering scaling theories of electrons in 2D in the presence of both interactions and disorder. We are
studying the effect of correlated disorder and Coulomb interactions in a 2DEG and have found new renormalization
group fixed point descriptions of electron systems which are metallic, and occur only in the presence of both
disorder and Coulomb interactions. We are applying our theory to the phenomenology of the superconductorinsulator transition, as well as the closely related problem of quantum Hall plateau transitions.

We showed using a very simple effective theory how superconductivity can be singularly enhanced at a
Pomeranchuk instability, provided that the Pomeranchuk transition is continuous. Another effect is that near such
transitions, Landau Fermi liquid behavior is destroyed. We have studied regimes where the enhancement of
superconductivity dominates over the destruction of Fermi liquid behavior and vive versa.

We have studied ultrathin oxide films via transport and resonant x-ray scattering, demonstrating a novel 1D
electronic/magnetic reconstruction at the atomic scale step edges of the films.

We are studying electrons tuned to van Hove singularities in 2D. Such systems allegedly exhibit higher temperature
superconductivity as well as competition to other broken symmetry phases, including magnetism and nematic order.
We are constructing a new scaling theory of such instabilities based on our studies of non-Fermi liquid behavior
near quantum critical points. Experiments are currently underway to study monolayer films of electronic materials
tuned via strain across the van Hove singularity.

We are combining transport with x-ray spectroscopy to examine the evolution of the electronic structure in oxide
films gated via solid and ionic-liquid structures.

We are studying the superconducting properties of quasi-one dimensional systems. We are studying instabilities to
triplet superconductivity, as well as the crossover from Luttinger liquid behavior at high temperatures to Fermi
liquid behavior at low temperature.
Further theoretical study of strongly enhanced superconducting instabilities near quantum critical points, the goal being
to identify limits where higher Tc superconductivity can emerge from a non-Fermi liquid regime, the parametric
enhancement of Tc and the effect of quantum critical fluctuations on the superfluid density. Further x-ray probes of
magnetic reconstructions in ultrathin magnetic oxide films are planned, first to examine static properties, and eventually
dynamical response. Increasing efforts to study magnetotransport in oxides on mesoscopic length scales are planned, as
well as the development and utilization of inelastic tunneling spectroscopy.
Collaborations
T.H. Geballe, S. Kachru, A. Kapitulnik, S. Kivelson, K. A. Moler, Y. Cui, T. P. Devereaux, Z. X. Shen, H. Durr, J.
Stohr, J. K. Norskov, A. Nilsson, M. Brongersma, C.-C. Kao, X. Qi (Stanford/SLAC); R. Thomale (ETF Lausanne); H.
Akiyama, A. Fujimori, Y. Iwasa, M. Kawasaki, K. Miyano, N. Nagaosa, M. Oshima, S. Shin, H. Takagi, Y. Tokura
(Tokyo); T. Kimura, Y. Wakabayashi (Osaka); H. Ohta (Nagoya); T. Egami, H. N. Lee (ORNL); J. Levy (Pittsburgh); Y.
Taguchi (RIKEN); D. A. Muller, L. F. Kourkoutis, D. G. Schlom (Cornell); B. G. Kim (Pusan); B. Keimer, J. Mannhart
(MPI Stuttgart); T. W. Noh (Seoul); C. Bernard (Fribourg); D. H. A. Blank, G. Rijnders (Twente); R. Ramesh
(Berkeley); J. H. Song (Chungnam); A. F. Hebard (Florida); G. A. Sawatzky (UBC); T. Banerjee (Groningen); A. J.
Millis (Columbia); F. Baumberger, J. M. Triscone (Geneva); S. J. Allen, D. D. Awschalom, C. Nayak, S. Stemmer, C.
Van de Walle (UCSB); S. Rajan (Ohio State); D. Jena (Notre Dame); C. H. Ahn, T. P. Ma (Yale); Y. Dagan (Tel Aviv);
J. Aarts, Y. M. Huber (Leiden); C. Attanasio (CNR-INFM); M. G. Blamire (Cambridge); B. Kalisky (Bar-Ilan); H.
Kumigashira (KEK, Japan); M. Yu. Kupriyanov (Moscow State); V. N. Kushnir (Belarus State); W. Meevasana
(Thailand Center of Excellence in Physics); R. J. Wijngaarden (Vrije).
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FWP#: 10069
Publications
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J. A. Mundy, Y. Hikita, T. Hidaka, T. Yajima, T. Higuchi, H. Y. Hwang, D. A. Muller, and L. F. Kourkoutis,
“Visualizing the Interfacial Evolution from Charge Compensation to Metallic Screening across the Manganite
Metal-Insulator Transition,” Nature Communications 5, 3464:1-6 (2014).
A. L. Fitzpatrick, S. Kachru, J. Kaplan, and S. Raghu, “Non-Fermi Liquid Behavior of Large N_B Quantum Critical
Metals,” Physical Review B 89, 165114 (2014).
S. Lederer, W. Huang, E. Taylor, S. Raghu, and C. Kallin, “Suppression of Spontaneous Currents in Sr2RuO4 by
Surface Disorder,” Physical Review B 90, 134521 (2014).
H. Watanabe, S. Parameswaran, S. Raghu, and A. Vishwanath, “Anomalous Fermi Liquid Phase in Metallic
Skyrmion Crystals,” Physical Review B 90, 045145 (2014).
Y. W. Xie, C. Bell, M. Kim, H. Inoue, Y. Hikita, and H. Y. Hwang, “Quantum Longitudinal and Hall Transport at
the LaAlO3/SrTiO3 Interface,” Solid State Communications 197, 25-29 (2014).
M. Minohara, T. Tachikawa, Y. Nakanishi, Y. Hikita, L. Fitting Kourkoutis, J.-S. Lee, C.-C. Kao, M. Yoshita, H.
Akiyama, C. Bell, and H. Y. Hwang, “Atomically Engineered Metal-Insulator Transition at the TiO2/LaAlO3
Heterointerface,” Nano Letters 14, 6743-6746 (2014).
A. Maharaj, P. Hosur, and S. Raghu, “Criss-Crossed Stripe Order from Interlayer Tunneling in Hole-doped
Cuprates,” Physical Review B 90, 125108 (2014).
Y. Yamada, H. K. Sato, Y. Hikita, H. Y. Hwang, and Y. Kanemitsu, “Photocarrier Recombination and Localization
Dynamics of LaAlO3/SrTiO3 Heterostructures,” Proceedings of the SPIE 8987, 898710:1-7 (2014).
Y. Takahashi, S. Chakraverty, M. Kawasaki, H. Y. Hwang, and Y. Tokura, “In-plane Terahertz Response of Thin
Film Sr2RuO4,” Physical Review B 89, 165116:1-5 (2014).
Y. Yamada, H. K. Sato, Y. Hikita, H. Y. Hwang, and Y. Kanemitsu, “Spatial Density Profile of Electrons Near the
LaAlO3/SrTiO3 Heterointerface Revealed by Time-Resolved Photoluminescence Spectroscopy,” Applied Physics
Letters 104, 151907:1-4 (2014).
A. G. Swartz, S. Harashima, Y. W. Xie, D. Lu, B. J. Kim, C. Bell, Y. Hikita, and H. Y. Hwang, “Spin Dependent
Transport Across Co/LaAlO3/SrTiO3 Heterojunctions,” Applied Physics Letters 105, 032406:1-4 (2014).
Y. Lei, Y. Z. Chen, Y. W. Xie, S. H. Wang, Y. Li, J. Wang, B. G. Shen, N. Pryds, H. Y. Hwang, and J. R. Sun,
“Visible Light Enhanced Field Effect at the LaAlO3/SrTiO3 Interface,” Nature Communications 5, 5554:1-5 (2014).
H. T. Yuan, X. Q. Wang, B. Lian, H. Zhang, X. Fang, B. Shen, G. Xu, Y. Xu, S. C. Zhang, H. Y. Hwang, and Y.
Cui, “Generation and Electric Control of Spin-Valley-Coupled Circular Photogalvanic Current in WSe2,” Nature
Nanotechnology 9, 851-857 (2014).
X. Liu, J.-H. Park, J.-H. Kang, H. T. Yuan, Y. Cui, H. Y. Hwang, and Mark L. Brongersma, “Quantification and
Impact of Nonparabolicity of the Conduction Band of Indium Tin Oxide on its Plasmonic Properties,” Applied
Physics Letters 105, 181117:1-4 (2014).
T. Yajima, M. Minohara, C. Bell, H. Kumigashira, M. Oshima, H. Y. Hwang, and Y. Hikita, “Enhanced Electrical
Transparency by Ultra-Thin LaAlO3 Insertion at Oxide Metal/Semiconductor Heterointerfaces,” Nano Letters 15,
1622-1626 (2015).
T. Yajima, Y. Hikita, M. Minohara, C. Bell, J. A. Mundy, L. F. Kourkoutis, D. A. Muller, H. Kumigashira, M.
Oshima, and H. Y. Hwang, “Controlling Band Alignments by Artificial Interface Dipoles at Perovskite
Heterointerfaces,” Nature Communications 6, 6759:1-5 (2015).
Z. Erlich, Y. Frenkel, J. Drori, Y. Shperber, C. Bell, H. K. Sato, M. Hosoda, Y. W. Xie, Y. Hikita, H. Y. Hwang,
and B. Kalisky, “Optical Study of Tetragonal Domains in LaAlO3/SrTiO3,” Journal of Superconductivity and Novel
Magnetism 28, 1017-1020 (2015).
V. Thareja, J. Kang, H. T. Yuan, K. M. Milaninia, H. Y. Hwang, Y. Cui, P. G. Kik, and M. L. Brongersma,
“Electrically Tunable Coherent Optical Absorption in Graphene with Ion Gel,” Nano Letters 15, 1570-1576 (2015).
T. Tsuyama, T. Matsuda, S. Chakraverty, J. Okamoto, E. Ikenaga, A. Tanaka, T. Mizokawa, H. Y. Hwang, Y.
Tokura, and H. Wadati, “X-Ray Spectroscopic Study of BaFeO3 Thin Films: An Fe4+ Ferromagnetic Insulator,”
Physical Review B 91, 115101:1-7 (2015).
S. C. Riggs, M. C. Shapiro, A. V. Maharaj, S. Raghu, E. D. Bauer, R. E. Baumbach, P. Giraldo-Gallo, M.
Wartenbe, and I. R. Fisher, “Evidence for a Nematic Component to the Hidden-Order Parameter in URu2Si2 from
Differential Elastoresistance Measurements,” Nature Communications 6, 6425 (2015).
P. Munkhbaatar, Z. Marton, B. Tsermaa, W. S. Choi, S. S. A. Seo, J. S. Kim, N. Nakagawa, H. Y. Hwang, H. N.
Lee, and K. Myung-Whun, “Room Temperature Optical Anisotropy of a LaMnO3 Thin-film Induced by Ultra-short
Pulse Laser,” Applied Physics Letters 106, 092907:1-4 (2015).
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SIMES: Two-Dimensional Chalcogenide Nanomaterials
FWP#: 100141
Two-Dimensional Chalcogenide Nanomaterials
Principal Investigator(s): Yi Cui (FWP lead), Harold Y. Hwang, Shoucheng Zhang, Jun-Sik Lee
Staff Scientists: Yasuyuki Hikita, Hongtao Yuan
Postdoctoral Scholars and Graduate Students: Wei Chen, Di Lu, Jie Sun, Chun Lan Wu, Gang Xu, Jung Ho Yu,
Jinsong Zhang
Visiting Physicists: Shougo Higashi, Alex Welch
Overview
Our long-term vision is to build a cutting-edge research program developing an exciting class of two dimensional
(2D) chalcogenide (O, S, Se, Te) nanomaterials, which can generate high impact on a wide range of DoE BES priorities
in materials design and control. Our central focus is understanding and utilizing the modification of the physical
properties of these materials by their heterogeneous ionic environment. Here this ionic environment is realized through
synthesis of heterostructured interfaces, electric double layer gating, electrochemical intercalation and chemical tuning.
Based on the past excellent research accomplishments in this area, the co-PI’s (Yi Cui, Harold Hwang, Jun-Sik Lee and
Shoucheng Zhang) integrate their research activity synergistically to explore an exciting territory of 2D nanomaterials
discovery, computational design, synthesis and novel properties.
To reach this long-term vision, this proposal outlines three thrusts of research to be conducted within the
next three years:
Thrust 1. Design and synthesis of novel 2D nanomaterials focusing on interfaces between different ionic
environments.
Thrust 2. Ionic tuning of 2D nanomaterials by electric double layer gating, electrochemical interaction
and chemical tuning.
Thrust 3. Probe and manipulate the exciting electronic and photonic properties of these novel materials.
This proposal well matches the priorities of DoE BES and the development plan for the Stanford Institute for Materials
and Energy Sciences (SIMES), the Materials Sciences Division at SLAC. It also integrates four co-located leading
scientists with materials, theory, and X-ray expertise into a team to address this timely research opportunity, via this
FWP on 2D chalcogenide nanomaterials.
Progress in FY2015

We have successfully demonstrated the generation and further electrical control of a spin-coupled valley
photocurrent, within an electric-double-layer transistor based on WSe2, whose direction and magnitude depend
on the degree of circular polarisation of the incident radiation and can be further modulated with an external
electric field. This room temperature generation and electric control of valley and spin photocurrent provides a
new property of electrons in transition-metal dichalcogenides systems, thereby enabling new degrees of control
for quantum-confined spintronic devices.

We have demonstrate a broadband photodetector using layered black phosphorus transistors which is
polarisation sensitive over a broad bandwidth from about 400 nm to 3750 nm. The polarisation‐
sensitivity is due to the strong intrinsic linear dichroism, which arises from the in‐plane optical
anisotropyofthismaterial.Inthistransistorgeometry,aperpendicularbuilt‐inelectricfieldinducedby
gatingcanspatiallyseparatethephoto‐generatedelectronsandholesinthechannel,effectivelyreducing
theirrecombinationrate,andthusenhancingtheperformanceforlineardichroismphotodetection.

We demonstrated atomically thin rhenium disulfide (ReS2) flakes with a unique distorted 1T structure, which
exhibit in-plane anisotropic properties that are induced by low lattice symmetry. We fabricated mono- and fewlayer ReS2 field effect transistors (FETs), which exhibit competitive performance with large current on/off
ratios (~108) and low subthreshold swings (100 mV/dec) at room temperature. The observed anisotropic ratio
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FWP#: 100141
along the two principle axes reaches 3.1, which is the highest among all known 2D semiconducting materials.
Furthermore, we successfully demonstrated an integrated digital inverter with good performance by utilizing
two ReS2 anisotropic FETs, suggesting the promising implementation of large-scale 2D logic circuits. Our
results underscore the unique properties of 2D semiconducting materials with low crystal symmetry, which can
be exploited for future novel electronic applications.

We discovered extraordinary light transmission through thin nanoplates of layered bismuth chalcogenides
bychemical intercalation of copper atoms, which is on the contrary to most bulk materials in which doping
reduces the light transmission. We discover substantial enhancement of light transmission and electrical
conductivity in ultrathin MoS2 nanosheets after Li intercalation, due to changes in band structure that reduce absorption upon intercalation and the injection of large amounts of free carriers. This dynamic tuning capability
via intercalation shows great potential in many applications. We also capture the first in-situ optical
observations of Li intercalation in MoS2 nanosheets, shedding lights on the dynamics of the intercalation
process and the associated spatial inhomogeneity and cycling-induced structural defects.

We examined the impact of intercalated lithium (Li) ions on the thermal properties of thin films of MoS2 down
to the order of tens of nanometers in thickness. We use in-situ time-domain thermoreflectance (TDTR) to
monitor changes in the thermal conductivity of MoS2 films (kMoS2) while simultaneously performing
intercalation and de-intercalation of Li+ ions. Changes in kMoS2 are dynamically measured by recording
changes in the ratio of the in-phase to out-of-phase voltage components of the reflected probe intensity at fixed,
short delay times. This ability to reversibly tune thermal conductivity via electrochemical modulation at the
nanoscale could enable new applications in energy conversion and thermal management, where the dynamic
control of heat transfer is a potentially useful feature.

We investigated the insulator-metal phase transition behavior of layered 2H-MoSe2 using pressure generated by
a Diamond Anvil Cell. We found that pressure allows MoSe2 to change from a highly anisotropic 2D layered
network to an isotropic 3D solid where the van der Waals gap is effectively closed. With continuous
contractions in lattice parameters under pressure, MoSe2 evolves from a semiconductor to a metal with the
“indirect” feature of its band structure being well preserved. Our results underscore pressure’s role in tuning the
mechanical, optical, and electronic properties of layered transition metal dichalcogenides.

We have successfully developed the synthesis and structural characterization of a family of 2D-layered metal
dichalcogenide films (MoS2, MoSe2, WS2, WSe2) whose crystal layers are perpendicular the the substrate
surface. We have measured the catalytic activity of hydrogen evolution of vertically aligned 2D-layered
dichalcoenide films. We showed that the edge exposure of this structure affords high activity of hydrogen
evolution and also present well-defined sample for quantifiying catalytically active sites.

We demonstrated the synthesis of vertical heterostructure of n-type MoS2 and p-type WSe2 with vertically
aligned atomic layers. The heterostructure synthesis is scalable to a large area over 1 cm2. We demonstrated the
pn junction diode behavior of the heterostructure device. This novel device geometry opens up exciting
opportunities for a variety of electronic and optoelectronic devices, complementary to the recent interesting
vertical heterostructures with horizontal atomic layers.

We explored the use of black phosphorus (BP) as an anode material for SIB and found the two-step reaction
mechanism of ‘intercalation’ and ‘alloying’. BP exhibits a high capacity (~2300 mA h g-1) upon its sodiation to
Na3P, even though the large anisotropic expansion occurs upon alloy reaction resulting in the main limitation to
utilize its full reversible capacity. In order to overcome this issue, we designed a new, sandwiched phosphorenegraphene structure. This newly developed material shows outstanding electrochemical properties with a high
specific capacity of 2440 mA h g-1 (calculated using P mass only) at a current densitiy of 0.05 A/g and an 83 %
capacity retention after 100 cycles.
Further experiments on growing intrisinc and doped layered materials including the magnetic-atom doping or
interrelation and copper into layer materials or strontium doping for topological superconductors. Demonstrationg of
electrochemical and strain tuning of layered materials for electrocatalysis. Further demonstration of the chemical and
electrochemical tuning of layered materials on the electronic, spintronic and optical properties. Further research on
electric double layer gating on 2D materials and field-induced superconductivity. Further experiments to use
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FWP#: 100141
intercalation to tune 2D material electrical, thermal and thermoelectric (Seebeck coefficient) properties to enhance the
ZT for more efficient thermoelectric harvesting.
Further study on electrocatalysis with 2D materials and experimental chemical and electrochemical tuning. Theorectical
and simulation understanding of the effect of chemical and electrochemical tuning on the electronic structure. ARPES
study of electronic structure of 2D materials. Further demonstrationof the chemical and electrochemical tuning of layered
materials on the electronic, spintronic and optical properties. Further research on electric double layer gating on 2D
materials and field-induced superconductivity.
Collaborations
S. Fan (Stanford), M. Brongersma (Stanford), Wendy L. Mao (Stanford), Y. L. Chen (Oxford), Z. X. Shen (Stanford).
Publications
1.
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H. T. Yuan, X. G. Liu, F. Afshinmanesh, W. Li, G. Xu, J. Sun, B. Lian, G. J. Ye, Y. Hikita, Z. X. Shen, S.-C.
Zhang, X. H. Chen, M. Brongersma, H. Y. Hwang, Y. Cui, Broadband linear-dichroic photodetector in a black
phosphorus vertical p-n junction. Nature Nanotechnology (2015) DOI: 10.1038/NNANO.2015.112.
H. T. Yuan, X. Q. Wang, B. Lian, H. J. Zhang, X. F. Fang, B. Shen, G. Xu, Y. Xu, S.-C. Zhang, H. Y. Hwang
and Y. Cui, Generation and electric control of spin-coupled valley current in WSe2. Nature Nanotechnology 9,
851–857 (2014).
H. T. Yuan, H. T. Wang, Y. Cui, Two-dimensional layered nanomaterials: toward property control via orbital
occupation and electron filling. Accounts of Chemical Research 48, 81-90 (2015).
H. T. Wang, H. T. Yuan, S. S. Hong, Y.B. Li, Y. Cui, Physical and chemical strategies for tuning twodimensional transition metal dichalcogenides properties. Chemical Society Reviews (2015) DOI:
10.1039/C4CS00287C.
Z. Zhao, H. J. Zhang, H. T. Yuan, S. B. Wang, Y. Lin, Q. S. Zeng, Z. Liu, K. D. Patel, G. K. Solanki, Y. Cui, H.
Y. Hwang, W. L. Mao. Pressure tuning the crystal structure and electronic state of MoSe2. Nature
Communications (2015) in press.
E. Liu, Y. Fu, Y. Wang, Y. Feng, Y. Pan, H. Liu, X. Wan, W. Zhou, B. Wang, Z. Cao, L. Wang, A. Li, J. Zeng,
F. Song, X. Wang, Y. Shi, H. T. Yuan, H. Y. Hwang, Y. Cui, F. Miao & D. Xing. Rhenium disulphide
anisotropic field-effect transistors and digital inverters. Nature Communications (2015) in press.
S. S. Hong, D. Kong, and Y. Cui, Topological insulator nanostructures, MRS Bulletin 39, 873 (2014)
J. Yao, K. J. Koski, W. Luo, J. J. Cha, L. Hu, D. Kong, V. K. Narasimhan, K. Huo, and Y. Cui, Optical
transmission enhancement through chemically tuned two-dimensional bismuth chalcogenide nanoplates, Nature
Communications 5, 5670 (2014).
H. Wang, Q. Zhang, H. Yao, Z. Liang, H.-W. Lee, P.-C. Hsu, G. Zheng, and Y. Cui, High Electrochemical
Selectivity of Edge versus Terrace Sites in Two-Dimensional Layered MoS2 Materials, Nano Letters (2014)
DOI:10.1021/NL503730C.
J. H. Yu, H. R. Lee, S. S. Hong, D. Kong, H.-W. Lee, H. Wang, F. Xiong, S. Wang, and Y. Cui, Vertical
Heterostructure of Two-Dimensional MoS2 and WSe2 with Vertically Aligned Layers, Nano Letters (2015)
DOI:10.1021/NL503897H.
H. Wang, C. Tsai, D. Kong, K. Chan, F. Abild-Pedersen, J. K. Norskov, and Y. Cui, Transition-metal Doped
Edge Sites in Vertically Aligned MoS2 Catalysts for Enhanced Hydrogen Evolution, Nano Research (2015)
DOI:10.1007/S12274-014-0677-7.
S. S. Hong, Y. Zhang, J. J. Cha, X.-L. Qi, and Y. Cui, One-Dimensional Helical Transport in Topological
Insulator Nanowire Interferometers, Nano Letters 14, 2815-2821 (2014).
H. Wang, Z. Lu, D. Kong, J. Sun, T. M. Hymel, and Y. Cui, Electrochemical Tuning of MoS2 Nanoparticles on
Three-Dimensional Substrate for Efficient Hydrogen Evolution, ACS Nano 8, 4940-4947(2014).
D. Kong, H. Wang, Z. Lu, and Y. Cui, CoSe2 Nanoparticles Grown on Carbon Fiber Paper: An Efficient and
Stable Electrocatalyst for Hydrogen Evolution Reaction, J. Am. Chem. Soc. 136, 4897-4900 (2014) DOI:
10.1021/ja501497.
J. P. Motter, K. J. Koski, and Y. Cui, General Strategy for Zero-Valent Intercalation into Two-Dimensional
Layered Nanomaterials, Chemistry of Materials 26, 2313-2317 (2014).
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FWP#: 100141
16. J. Sun, G. Zheng, H.-W. Lee, N. Liu, H. Wang, H. Yao, W. Yang and Y. Cui, Formation of Stable PhosphorusCarbon Bond for Enhanced Performance in Black Phosphorus Nanoparticle-Graphite Composite Battery
Anodes, Nano Letters DOI:10.1021/NL501617j (2014).
17. N. Liu, K. Kim, P.-C. Hsu, A. N. Sokolov, F. L. Yap, H. T. Yuan, Y. W. Xie, H. Yan, Y. Cui, H. Y. Hwang,
and Z. N. Bao, Large-Scale Production of Graphene Nanoribbons from Electrospun Polymers. J. Am. Chem.
Soc., 136, 17284–17291 (2014).
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SIMES: Joint Center for Energy Storage Research
FWP#: 100146
Joint Center for Energy Storage Research (JCESR)
Principal Investigator(s): Yi Cui
Postdoctoral Scholars and Graduate Students: Weiyang Li, Hongbin Yao
Overview
The JCESR aims to discover and to study energy storage systems for transportation and grid-scale storage. It integrates a
large number of multi-institutional research programs to work together. Yi Cui is one of several PI’s conducting research
to support this goal.
Progress in FY2015
Lithium polysulfides are intermediate species generated in Li-S battery during cycling. Our previous research (Y. Yang,
G. Zheng, Y. Cui, Energy Environ. Sci. 2013, 6, 1552) demonstrated a novel lithium/polysulfide semi-liquid battery
system for grid-scale energy storage using lithium polysulfide (Li2S8) and passivated metallic lithium as the catholyte
and the anode, respectively. However, practical applications of rechargeable lithium metal-based batteries have been
hindered by the formation of dendritic and mossy lithium and associated electrolyte decomposition, resulting in safety
concerns and low Coulombic efficiency. Most recently, we demonstrate that lithium dendrite growth can be effectively
suppressed via manipulating the chemical reactions of lithium, lithium polysulfide, and lithium nitrate (LiNO3). Both
Li2S8 and LiNO3 were used as additives to the ether-based electrolyte, which enables a synergetic effect leading to the
formation of a stable and uniform solid electrolyte interphase layer on lithium surface that can greatly minimize the
electrolyte decomposition and prevent dendrites from shooting out. By simply manipulating the concentrations of Li2S8
and LiNO3, we show that the formation of lithium dendrites can be prevented at a practical current density of 2 mA cm-2
up to a deposited areal capacity of 6 mAh cm-2. We also demonstrate excellent cyclability: the Coulombic efficiency can
be maintained at >99% for over 300 cycles at 2 mA cm-2 with a deposited capacity of 1 mAh cm-2. Even for cyclic
deposition of a high areal capacity of 3 mAh cm-2, the average Coulombic efficiency can be as high as 98.5% over 200
cycles (and is higher at ~99.0% between 70 and 200 cycles).
In addition, we demonstrate that the precipitation of lithium polysulfide in Li-S battery can be controlled through the
electrode design. We propose the tin-doped indium oxide (ITO)-carbon hybrid interface design to understand the
spatially controlled deposition of polysulfides on the surface of electrodes and demonstrate its feasibility to improve the
performance of Li-S batteries. We show a clear visual evidence that these solid species deposit preferentially onto ITO
instead of carbon during electrochemical charge/discharge of soluble polysulfides. To incorporate this concept of spatial
control into more practical battery electrodes, we further prepare carbon nanofibers with ITO nanoparticles decorating
the surface as hybrid three-dimensional electrodes to maximize the number of deposition sites. With 12.5 µl of 5M Li2S8
as the catholyte and a rate of C/5, we can reach the theoretical limit of Li2S8 capacity ~1470 mAh g-1 (sulfur weight)
under the loading of hybrid electrode only at 4.3 mg cm-2).
Moreover, we report a novel carbon cluster structure inspired by pomegranate fruits as a framework for sulfur
encapsulation for Li-S battery. The resulting sulfur cathode could deliver a high reversible capacity of over 700 mAh/g at
an ultrahigh current of 3C (or 10 mA/cm2 equivalent) with a high sulfur mass loading of 2 mg/cm2, corresponding to a
volumetric energy density of 1320 Wh/L. The space-efficient packing of the clusters allows for a high tapped density,
excellent electrical contact, and the complicated nanoarchitecture effectively inhibits polysulfides dissolution. The
enhanced electrochemical behavior shows that this sulfur cathode with pomegranate-like cluster structure represents an
effective strategy in improving Li-S battery performance.
Finally, instead of using lithium polysulfide and sulfur as cathode materials for Li-S battery, fully lithiated lithium
sulfide (Li2S), with its high theoretical specific capacity of 1,166 mAh/g, represents an attractive cathode material
because of its compatibility with safer lithium metal-free anodes. Moreover, since Li2S is already in its fully lithiated and
fully expanded state, it circumvents the volumetric expansion problem in S cathodes, thus minimizing structural damage
at the electrode level. We demonstrate the encapsulation of Li2S with conductive polymers or graphene oxides to
improve the conductivity and retard the polysulfides dissolution. Using the Li2S-polypyrrole composites as a cathode
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SIMES: Joint Center for Energy Storage Research
FWP#: 100146
material, we demonstrate a high discharge capacity of 785 mAh g-1 of Li2S (~1,126 mAh g-1 of S) with stable cycling
over prolonged 400 charge/discharge cycles. Using the Li2S-graphene oxide composites as a cathode material, we
demonstrate a high discharge capacity of 782 mAh g-1 of Li2S (~1,122 mAh g-1 of S) with stable cycling performance
over 150 charge/discharge cycles.
We will continue to develop method to find the perfect encapsulating materials that have high electronic/ionic
conductivity to achieve a more complete coating on Li2S to further mitigate against polysulfide dissolution into the
electrolyte. We plan to develop additional cost-effective methods to control the depostion sites of lithium polysulfides
and systematically investigate the effect of different materials in retarding the polysulfide dissolution. We also plan to
develop new methods to lower the activation potential of Li2S and identify any critical size for activation.
We plan to pair the stable-cycling Li2S cathodes with lithium metal-free anodes (such as silicon or tin) to achieve a fullcell configuration.
Collaborations
1. Prof. Yet-Ming Chiang (MIT).
2. Prof. Qianfan Zhang (Beihang University, China).
Publications for FY15 (Oct 1st 2014 to date)
1.
Z. W. Seh, H. Wang, P. C. Hsu, Q. Zhang, W. Li, G. Zheng, H. Yao, Y. Cui, “Facile synthesis of Li2Spolypyrrole composite structures for high-performance Li2S cathodes.” Energy Environ. Sci. 2014, 7, 672-676.
2.
Z. W. Seh, H. Wang, N. Liu, G. Zheng, W. Li, H. Yao, Y. Cui, “High-capacity Li2S-graphene oxide composite
cathodes with stable cycling performance.” Chem. Sci. 2014, 5, 1396-1400.
3. H. Yao, G. Zheng, P. C. Hsu, D. Kong, J. J. Cha, W. Li, Z. W. Seh, M. T. McDowell, K. Yan, Z. Liang, V. K.
Narasimhan, Y. Cui, “Improving lithium-sulphur batteries through spatial control of sulphur species deposition
on a hybrid electrode surface.” Nat. Commun. 2014, 5: 3943.
4.
W. Li, Z. Liang, Z. Lu, H. Yao, Z. W. Seh, K. Yan, G. Zheng, Y. Cui, "A Sulfur Cathode with PomegranateLike Cluster Structure", Adv. Energy Mater. 2015, DOI:10.1002/AENM.201500211.
5.
W. Li, H. H. Yao, K. Yan, G. Y. Zheng, Z. Liang, Y.-M. Chiang, and Y. Cui, “The Synergetic Effect of
Lithium Polysulfide and Lithium Nitrate to Prevent Lithium Dendrite Growth” Nat. Commun. 2015, In press.
46
SIMES: Nanostructured Design of Sulfur Cathodes for High Energy Lithium-Sulfur Batteries
FWP#: 100185
Nanostructured Design of Sulfur Cathodes for High Energy
Lithium-Sulfur Batteries
Staff Scientists and Academic Research Associates: Seok Woo Lee
Postdoctoral Scholars and Graduate Students: Galvin Cooper, Jang Soo Lee, Sang Han Lee, Dingchang Lin, Frank
Luciano, Zhi Wei Seh, Wesley Zheng, Denys Zhuo
Visiting Physicists: Xinyong Tao
Overview
The EERE Vehicle Technology Program has supported research in high-energy lithium-based battery technologies for
plug-in-hybrid-electric (PHEV) and electric vehicles (EV), calling for high capacity electrode materials. In this project,
we will conduct research on developing sulfur cathodes from the perspective of nanostructured materials design, which
will be used to combine with lithium metal anodes to generate high-energy lithium-sulfur batteries. Specifically, we will
study the fundamental of lithium-sulfur reaction and design sulfur nanostructures and multifunctional coating to
overcome the issues related to volume expansion, polysulfide dissolution and insulating nature of sulfur. We aim to
enable high capacity and long cycle life sulfur cathodes
Progress in FY2015
In order to improve the performance of sulfur cathode, we develope a 3-D electrode structure to achieve both sulfur
physical encapsulation and polysulfides binding simultaneously. The electrode is based on hydrogen reduced TiO2 with
an inverse opal structure that is highly conductive and robust toward electrochemical cycling. The openings at the top
surface allow sulfur infusion into the inverse opal structure. In addition, chemical tuning of the TiO2 composition
through hydrogen reduction was shown to enhance the specific capacity and cyclability of the cathode. With such TiO2
encapsulated sulfur structure, the sulfur cathode could deliver a high specific capacity of 1100 mAh/g in the beginning,
with a reversible capacity of 890 mAh/g after 200 cycles of charge/discharge at a C/5 rate. The Coulombic efficiency
was also maintained at around 99.5% during cycling. The results showed that inverse opal structure of hydrogen reduced
TiO2 represents an effective strategy in improving lithium sulfur batteries performance.
We further discover that conductive Magnéli phase Ti4O7 can function as highly effective matrix to bind with sulfur
species. Compared with the TiO2-Sulfur composite cathode, the Ti4O7-S cathodes exhibit higher reversible capacity and
improved cycling performance. It delivers high specific capacities at various C-rates (1342, 1044, and 623 mAh/g at 0.02,
0.1, and 0.5 C, respectively) and remarkable capacity retention of 99% (100 cycles at 0.1 C). The superior properties of
Ti4O7-S are attributed to the strong adsorption of sulfur species on the low-coordinated Ti sites of Ti4O7. Our study
demonstrates the importance of surface coordination environment for strongly influencing the S-species binding. These
findings can be also applicable to numerous other metal oxide materials.
Besides the study of sulfur cathode, fully lithiated lithium sulfide (Li2S) is currently being explored as a promising
cathode material for emerging energy storage applications. Like their sulfur counterparts, Li2S cathodes require effective
encapsulation to reduce the dissolution of intermediate lithium polysulfide species into the electrolyte. We demonstrate
the encapsulation of Li2S cathodes using two-dimensional layered transition metal disulfides that possess a combination
of high conductivity and strong binding with lithium sulfide and polysulfide species. In particular, using titanium
disulphide as an encapsulation material, we demonstrate a high specific capacity of 503 mAh/g (based on Li2S mass)
under high C-rate conditions (4C) as well as high areal capacity of 3.0 mAh/cm2 under high mass-loading conditions (5.3
mg Li2S/cm2).
Moreover, we demonstrate the role of the separator in the capacity decay of the lithium-sulfur battery, namely that it can
accommodate a large amount of polysulfides inside which then precipitates as a thick layer of inactive S-related species.
We develope the use of a thin layer of conductive coating on the separator that can prevent the formation of the inactive
47
SIMES: Nanostructured Design of Sulfur Cathodes for High Energy Lithium-Sulfur Batteries
FWP#: 100185
S-related species layer. The large surface area of the conducting coating increased the utilization of the polysulfides
accommodated in the separator. We show that the specific capacity and cycling stability of the lithium-sulfur battery are
both improved significantly compared to the battery with a pristine separator.
Understanding the behavior of soluble intermediate lithium polysulfide species is vitally important for improving the
electrochemical performances of lithium-sulfur batteries. We further explore a simple in-operando lithium-sulfur cell
design to enable direct visualization of the formation of the soluble polysulfide species and their temporal and spatial
distribution over the entire discharge/ charge cycle under an optical microscope. Our results reveal detailed evidence of
electrochemical degradation in lithium-sulfur batteries and help us to understand the improvements in electrochemical
performances using advanced lithium-sulfur cell designs. As examples, we show that a cathode consisting of hollow
sulfur nanoparticles with a conductive polymer coating exhibits significantly reduced dissolution of polysulfides into the
electrolyte, and thus superior electrochemical performance could be achieved. Moreover, the trapping of soluble
polysulfide species in the cathode side was also confirmed in our designed in-operando lithium-sulfur cell with a Nafion
modified separator.
Future directions include: 1) increasing the mass and the percentage of sulfur loading in the electrode; 2) tuning different
electrolyte additives to improve the Coulombic efficiency and cycling stability; 3) screening a wide range of oxide and
sulfide materials for effective polysulfide trapping.
We plan to develop approaches to prevent the lithium dendrites growth on lithium metal anodes in lithium-sulfur
batteries. We also plan to combine sulfur cathodes with lithiated anodes, such as lithiated silicon, to assemble full batteries to
eliminate the safety concern of using lithium metal.
Collaborations
1.
2.
Prof. Qianfan Zhang (Beihang University, China).
Prof. Weihui Zhang (Zhejiang University of Technology, China)
1.
2.
3.
4.
5.
Z. Liang, G. Zheng, W. Li, Z. W. Seh, H. Yao, K. Yan, D. Kong, and Y. Cui, "Sulfur Cathodes with Hydrogen
Reduced Titanium Dioxide Inverse Opal Structure", ACS Nano, 2014, 8, 5249-5256.
X. Tao, J. Wang, Z. Ying, Q. Cai, G. Zheng, Y. Gan, H. Huang, Y. Xia, C. Lian, W. Zhang and Y. Cui, "Strong
Sulfur Binding with Conducting Magneli-Phase TinO2n-1 Nanomaterials for Improving Lithium-Sulphur
Batteries", Nano Letters, 2014, 14, 5288-5294.
H. Yao, K. Yan, W. Li, G. Zheng, D. Kong, Z. W. Seh, V. K. Narasimhan, Z. Liang, and Y. Cui, "Improved
lithium-sulfur batteries with a conductive coating on the separator to prevent the accumulation of inactive Srelated species at the cathode-separator interface", Energy & Environmental Science, 2014, 7, 3381-3390.
Z. W. Seh, J. H. Yu, W. Li, P.-C. Hsu, H. Wang, Y. Sun, H. Yao. Q. Zhang, and Y. Cui, "Two-dimensional
layered transition metal disulphides for effective encapsulation of high-capacity lithium sulphide cathodes",
Nature Communications, 2014, 5: 5017.
Y. Sun, Z. W. Seh, W. Li, H. Yao, G. Zheng, and Y. Cui, "In-operando optical imaging of temporal and spatial
distribution of polysulfides in lithium-sulfur batteries", Nano Energy, 2015, 11, 579-586
48
SIMES: Pre-Lithiation of Silicon Anode for High Energy Li Ion Batteries
FWP#: 100186
Pre-Lithiation of Silicon Anode for High Energy Li Ion
Batteries
Postdoctoral Scholars and Graduate Students: Yuzhang Li, Zheng Liang, Dingchang Lin, and Jie Zhao
Overview
Prelithiation of high capacity electrode materials such as Si is an important means to enable those materials in high
energy batteries. Here we explore several methods of prelithiation in order to understand their impact on the
electrochemical property and cyclability of Si anodes. We aim to identify the best and most practical prelithiation
methods.
Progress in FY2015
Rapid progress has been made in realizing battery electrode materials with high capacity and long-term cyclability in the
past decade. However, the problem of irrerversible capacity loss in the first cycle remains unresolved. Prelithiation is
becoming an important strategy to compensate for this lithium loss in lithium-ion batteries, particularly during the
formation of solid electrolyte interphase (SEI) from reduced electrolytes in the first charging cycle. We demonstrated
that thermal-alloying synthesized LixSi nanoparticles (NPs) can serve as a high-capacity (>2200 mAh/g Si) prelithiation
reagent although its chemical stability in the battery processing environment remained to be improved. Therefore, we
developed a surface modification method to enhance the stability of LixSi nanoparticles by exploiting the reduction of 1fluorodecane on the LixSi surface to form a continuous and dense coating, through a similar reaction process to SEI
formation. The coating, consisting of LiF and Lithium alkyl carbonate with long hydrophobic carbon chains, serves as an
effective passivation layer underambient environment. Remarkably, artificial-SEI protected LixSi NPs show a high
prelithiation capacity of 2100 mAh/g with negligible capacity decay in dry air after 5 days and maintain a high capacity
of 1600 mAh/g in humid air (~10% RH). Silicon, tin and graphite were successfully prelithiated with these NPs to
eliminate the irreversible first cycle capacity loss. Thus, incorporation of coated LixSi NPs is a promising approach that
may enable the commercial implementation of high-capacity nanostructured materials with large irreversible capacity
loss during the first cycle, which is a significant step towards high-energy-density Li-ion batteries.
We will continue to develop different kinds of prelithiation reagents. The target is to develop high capacity prelithiation
reagents from low cost materials. Ambiant air stability of prelithiation reagents will be enhanced by different coatings.
Finally, it should be stable in the ambient air for at least 6 h. We will continue to evaluate these particles blended with
Si, Tin and carbon anodes.
Different nanostructures will be ultilized to achieve fully lithiated Si with stable cycling performance. This material itself
will be used as anode material and paired with high capacity lithium-free cathode materials, such as Sulfur, to realize
new generation high-energy density lithium ion battery.
Collaborations
None.
49
SIMES: Pre-Lithiation of Silicon Anode for High Energy Li Ion Batteries
FWP#: 100186
1. Zhao, J. et al. Dry-air-stable lithium silicide–lithium oxide core–shell nanoparticles as high-capacity
prelithiation reagents. Nat. Commun. 5 (2014).
2. Zhao, J. et al. Artificial Solid Electrolyte Interphase Protected LixSi Nanoparticles: An Efficient and
Stable Prelithiation Reagent for Lithium-ion Batteries. Manuscript under review.
50

SIMES Field Budget Reports-June 2015

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