Lecture of Suderow at Cytef 2012

LABORATORIO DE BAJAS TEMPERATURAS:
CERCA DEL CERO ABSOLUTO
Hermann Suderow
Laboratorio de Bajas Temperaturas
Departamento de Física de la Materia Condensada
Instituto de Ciencia de Materiales Nicolás Cabrera
Universidad Autónoma de Madrid (UAM)
LABORATORIO DE BAJAS TEMPERATURAS:
CERCA DEL CERO ABSOLUTO
 Historia y tecnología del helio liquido
 Puntos fríos en el mK : 3He – 4He
 Superconductividad
 Microscopía de la superconductividad
Lord Rayleigh at the Royal Institution
1908. Helio líquido
1911. Superconductividad en Hg
Kamerlingh
Onnes
Van der Waals
"Helium is no longer a rare element"
"While it was going on," Cady said, "we decided to take
advantage of [Sir James] Dewar's recently published
discovery that coconut charcoal would adsorb all gases
[in the atmosphere] except helium, hydrogen, and neon
very completely at the temperature of boiling liquid air"
(-310 F).
After making some coconut charcoal and building a
glass apparatus to handle the gases, Cady and
McFarland proceeded to immerse glass bulbs of the
Dexter gas in liquid air and allowed them to stand for
some time. … On Dec. 7, 1905, Cady and McFarland
found that "instantly the yellow of the helium flashed up
and the spectroscope showed all the lines of helium."
The dominant spectroscopic line was identical to that
found almost 40 years earlier in the spectroscopic
analysis of the Sun that led to the extraterrestrial
discovery of helium. The total amount of helium present
in the Dexter gas was an astonishing 1.84%.
Less than a month later, on January 1, 1906, E.H.S.
Bailey, the chemistry department chair at Kansas, read
a paper by Cady and McFarland describing their
remarkable discovery before an ACS national meeting
in New Orleans.
…"assures the fact that helium is no longer a rare
element, but a common element, existing in goodly
quantity for uses that are yet to be found for it."
Heike Kamerlingh‐Onnes
y su ayudante Mr.Flim
2008 – centenario IIR
1908 – centenario primera licuación del helio
Kamerlingh Onnes
•
•
•
•
Primera cátedra en Física experimental en Holanda
Licuación de aire en 1892
Licuación de hídrógeno en 1906
10 de Julio de 1908: Licuación de helio
1908 en la ceremonia de inauguración del International
Congress of Refrigeration, H. Kamerlingh Onnes
propone:
“The creation of an international organization of refrigeration
which would further the work of the congress”
He insisted that one of the commissions be devoted to
scientific problems.
Dewar
Sir J. Dewar
R. Burger
Dewar modernos para helio líquido
Helio
Vacío
Nitrógeno
Vacío
H. Kamerlingh Onnes y la Física española
Kamerlingh Onnes, H. and J. Palacios Martinez,
Vapor pressure of hydrogen and new determinations in the liquid hydrogen region
(in Spanish)
Anales de la Real Sociedad Española de Fisica y Quimica., 1922. 20: p. 233-42
Blas Cabrera
J. Palacios
Martínez
Nicolás Cabrera
DESARROLLO DE CRIOGENIA
The SEGAINVEX team (headed by M. Pazos)
Durante 10 años, H.
Kammerlingh-Onnes
trabajó con solo 60 cm3
de helio líquido
En la UAM, hoy se licuan
30 000 000 cm3
de helio líquido cada año
LBTUAM works for industry (e.g. EADS)
LBTUAM belongs to REDLAB (lab nr 287) http://www.madrimasd.org/Laboratorios/default.asp
Técnicas de enfriamiento
• Evaporación
4He
3He
1K
250 mK
• Dilución de 3He en 4He
5 mK
• Desimanación adiabática
< 1 mK
• Pomeranchuk
<< 1 mK
LABORATORIO DE BAJAS TEMPERATURAS:
CERCA DEL CERO ABSOLUTO
 Historia y tecnología del helio liquido
 Puntos fríos en el mK : 3He – 4He
 Superconductividad
 Microscopía de la superconductividad
4He
3He
3He
4He
Cooling technique
Fase concentrada
3He
in 4He
Fase diluida
H  TS  T S 3 He diluido  S 3 He 
S T , x  
Cómo forzar el paso de 3He del concentrado al diluido ?
2
2
R
T
TF x 
From A.T.M. de Waele
Dilución de 3He en 4He : 1962
H. London
1951
F. London
Dilución de 3He en 4He : 1962
Fase concentrada
Fase diluida
Cómo forzar el paso de 3He del concentrado al diluido ?
PCM
R
 PE  TCM xDCM  TE xDE 
V4
Equilibrio:
PCM  PE  0
Con
6.4% 3He en 4He
Cámara de
mezcla
1% 3He en 4He
Evaporador
TCM  0.01K
TE  0.7 K
Cómo forzar la dilución de 3He concentrado en 3He diluido ?
PCM
R
 PE  TCM xDCM  TE xDE 
V4
Bombeando:
PCM  PE  1.6kPa
6.4% 3He en 4He
Cámara de
mezcla
0% 3He en 4He
Columna de 70 cm de 4He:
Evaporador
1kPa
Dilución - Evaporación
Fase concentrada
T2
Potencia enfriamiento (W)
Fase diluida
800
exp (-1/T)
Evaporación
3
He
Dilución
600
MX400
400
200
K25
0
0.0
0.2
Temperatura
0.4
El criostato de dilución
Cryogenic vaccum
T 
pV  p0  
 T0 
Cp / R
e
L0  1 1 
  
R  T0 T 
Vacío casi perfecto en el mK
Criogenia de dilución
NO HELIUM BATH
PULSE TUBE
Entorno
limpio, estable, fiable, versátil
ESA PLANCK
Criogenia de dilución en el LBTUAM
- 100 mK + 10 T (2001) SEGAINVEX
- 7 mK + 9 T
- 7 mK + 9 T
- 100 mK + 5 T + 1 T + 1 T
Por qué el milikelvin ?
“While the number of scientists interested in
the thermodynamics of acheiving low
temperatures is decreasing, many more are
interested in using these refrigerators to
perform experiments in the mK range.”
Innovating for nanotechnology applications
Our recent change of company name, from Superconductivity to NanoScience, is a
recognition of our increasingly important role in providing sample environments that enable
world-leading research in nanotechnology. Of course this encompasses many areas of
research that have evolved as important fields, within the broad scope of nanotechnology,
and we have pioneered many of the solutions which are now key tools in this area. Notable
amongst these are our optical spectroscopy cryogenic systems and our ultra low
temperature platforms. In particular we are celebrating the 40th anniversary of the
development of the dilution refrigerator this year, a product range that continues to
benefit from our innovative approach.
La “criofobia”
Sevilla 2008
LBTUAM
Programas de investigación europeos, nacionales y regionales
Colaboración con grupos teóricos
Acceso a grandes instalaciones
Dos puntos fríos a 7mK
con 0.4mW de capacidad de enfriamiento a 100mK
Una de las mayores capacidades de
enfriamiento que se pueden obtener con
la tecnología actual.
First cool down
Temperature (K)
100
10
1
0.1
Present base temperature : 8 mK
0.01
0
1
2
3
4
5
6
Time (hours)
7
8
9
http://www.uam.es/citecnomik
http://www.uam.es/inc
T
300 K
10 K
7 mK
H
17 T
P
500 kbar
Transporte y
magnetismo
Microscopía a escala atómica
Termodinámica
hermann.suderow@uam.es
Working for industry
Herschel y Planck ESA
http://www.uam.es/inc
•
Ofertar formación en las tecnologías que se utilizan en los laboratorios del INC.
•
Poner en contacto a investigadores en Ciencia de Materiales reconocidos internacionalmente,
con tecnólogos de otros laboratorios, instituciones y empresas.
•
Desarrollar una escuela de instrumentación avanzada para el negocio de la Ciencia.
http://www.uam.es/citecnomik
http://www.uam.es/inc
T
300 K
10 K
7 mK
H
17 T
P
500 kbar
Transporte y
magnetismo
Microscopía a escala atómica
Termodinámica
hermann.suderow@uam.es
LABORATORIO DE BAJAS TEMPERATURAS:
CERCA DEL CERO ABSOLUTO
 Historia y tecnología del helio liquido
 Puntos fríos en el mK : 3He – 4He
 Superconductividad
 Microscopía de la superconductividad
AN INTERESTING MACROSCOPIC QUANTUM PHENOMENON
Heike Kamerlingh-Onnes, 1911
Applications of superconductivity
1. Zero resistance
2. Quantum coherence
1. Industry (e.g. energy)
2. Instrumentation (e.g. SQUID) metrology
3. “Big Science”
Efecto del campo magnético. Anillo superconductor (R=0, M=‐B)
By 1914 Onnes established a permanent current, or what he called a
“persistent supercurrent,” in a superconducting coil of lead. The coil
was placed in a cryostat at low temperature, with the current being
induced by an external magnetic field. With no resistance, the
electrons in the coil were free to continue to flow indefinitely. After
seeing the current, Austrian-Dutch physicist Paul Ehrenfest wrote to
Nobel physicist Hendrik Lorentz in the Netherlands, “It is uncanny to
see the influence of these ‘permanent’ currents on a magnetic needle.
You can feel almost tangibly how the ring of electrons in the wire turns
around, around, around—slowly, and without friction.”
Onnes
Weiss
Einstein
Ehrenfest
Langevin
1932 : Demostración de la superconductividad en la Royal Institution
Superconductores de tipo I y de tipo II
Shubnikov y Abrikosov
Tipo I
- efecto Meissner, diamagnetismo perfecto
H
Tipo I
H
HC
N
HC = 100 - 1000 G
S
0
TC
H
HC2
T
Tipo II
H
N
HC
HC1 < 100 G
HC2 = 104 - 105 G
HC1
Tipo II
- estado mixto, vórtices
S
0
TC
T
Applications of superconductivity
Applications of superconductors : “Big Science”
La superconductividad : transformando la red eléctrica ?
Smart grid
Tecnología superconductora:
Generación, almacenamiento, distribución, conversión, usuario final
Estrategia ??
Nuevos materiales Técnicas criogénicas
Aplicaciones de la superconductividad
Pulse tube
“Evercool”
Plantas de licuación helio
Nanoscopic
cooling
Campo
magnético
Corriente
Presión
Superconductores de tipo I y de tipo II
Shubnikov y Abrikosov
Tipo I
- efecto Meissner, diamagnetismo perfecto
H
Tipo I
H
HC
N
HC = 100 - 1000 G
S
0
TC
H
HC2
T
Tipo II
H
N
HC
HC1 < 100 G
HC2 = 104 - 105 G
HC1
Tipo II
- estado mixto, vórtices
S
0
MICROSCOPIA DE VÓRTICES
TC
T
Microscopic theory
J.Bardeen, L. Cooper, J. Schrieffer (BCS, 1957)
Superconductor
  e
i
Cooper pairs
S=0
L=0
   k ,  k , 
 2
Ek     ,  (k )
2
k
N (E) 
E
E 2  2
 BCS  1.76k BTc
superconductores
Sonido producido solo por el motor
Sonido producido por el avión
Electron tunneling
I (V , z )  VN ( E F )e 1.025
nA - pA
z
Low temperature spectroscopy
87 eV = 1 K
N (E) 
   k ,  k , 
E
3
=1mV
T=0.3 K
T=1 K
2
1
0-4 -3 -2 -1 0
1
2
Bias voltage (eV/0)
E 
2
Normalized tunnelling conductance
dI
f ( E  eV )
  N (E)
dE
dV
V
4
2
  e
i
 2
Ek   k2   ,  (k )
N ( E ; x, y )
3
4
Microscopy of the superconducting gap in type II materials
H
Mixed state
Hc2
Normal
phase
Mixed
state
H
Meissner state
Hc
Hc1
Meissner state
Tc T
H
d(nm)  50 / H(T)
2
Ψ  ns
d
H

J
r

J
  e
i
   k ,  k , 
N (E) 
E
E 2  2
0
H c2 
2 2
Microscopy
Optical, SEM, SPM
SPM at cryogenic temperatures
Cryogenic operation of a scanning probe microscope eliminates Brownian
motion altogether, provides for resolution in energy and enables macroscopic
quantum behavior
Atomic scale manipulation with cryogenic scanning probe microscopy
T=4.2 K
D. Eigler, IBM
Cryogenic scanning probe microscopy eliminates
Brownian motion altogether and
enables macroscopic quantum behavior
50
LABORATORIO DE BAJAS TEMPERATURAS:
CERCA DEL CERO ABSOLUTO
 Historia y tecnología del helio liquido
 Puntos fríos en el mK : 3He – 4He
 Superconductividad
 Microscopía de la superconductividad
The vortex lattice through STM
Measure far below Tc (here 7 K), high mechanical stability of tip-sample
Cryogenic scanning probe microscopy eliminates Brownian motion altogether,
provides for resolution in energy and enables macroscopic quantum behavior
pA
Efficient microscopy of superconducting vortices
pm stability
mK temperatures
100 mK is the target
Microscope
design
Cooling and
environment
Principle of operation of a scanning tunneling microscope
Fine positioning piezoelectrics
+
Coarse motor
Z
nm
x, y  20
V
Scanning window in the
m range with sub atomic
resolution
z
y
x
Position
without
heating with
nm resolution
Y
X
Designing a cryogenic scanning tunneling microscope
Stiffness
fvibration isolation
Stiff and light
Soft and heavy
fmicroscope
Tip-sample motion shall be in phase
1
f0 
2
k
meff
Dilution refrigerators of the LBTUAM
Mezclas de 3He y 4He
5 meter long flexible pumping line
4He 5 meter long flexible pumping line
3He rotary
pump
L
N Classical Oxford
Instruments dilution
refrigeration technology
Development:
Support
Pumping
Liquid consumption
Sample holders
Gas handling
system
3He‐4He mixture reservoirs
Separate building
rotary
pump
STM holder for dilution refrigeration
Mezclas de 3He y 4He
 STM head is posed on fiber glass loom
 Specific precision motion system using a series of ropes with a room
temperature actuator without measurable heating at 100 mK
STM/S head for dilution refrigeration
MADRID LBTUAM
- 100 mK + 9 T
- 300 mK + 13 T
- 10 mK + 9 T (current flow)
- 100 mK + 3D VECTOR MAGNET
In situ tip and sample preparation methods
2 m
STM electronics at LBTUAM
Mezclas de 3He y 4He
Switchable
filter’
Motor Z’
PA243
I-V converter
Tunnel current
RF
filters
6x
PA243
RF filters
Bias voltage
RF
filters
Industrial
PC
DAC
ADC
OP27
RF
filters
Power
supply
+/- 15 V
RF
filters
…
6 PIEZO
SCANNING
DRIVES
Power
supply
+/- 15 V
+/- 140 V
Power
supply
Resolution in spectroscopy of <15 eV (<150 mK)
Home made equipment: design, construct, test
SEGAINVEX
100 mK
100 mK
+ 3D (5 T + 1 T + 1 T)
AUTOMATIZED
3D VECTOR MAGNET
Cryogenic scanning probe microscopy eliminates Brownian motion altogether,
provides for resolution in energy and enables macroscopic quantum behavior
pA
Efficient microscopy of superconducting
vortices
pm stability
ten eV resolution
100 mK is the target
Microscope
design
Cooling and
environment
Results
0.35 nm
1.25 nm
0.29 nm
Atomic scale imaging at 100 mK
c
a
Se
Nb
b
1/CDW
1/a
2H‐NbSe2
1.7nm
2H‐NbS2
CDW  3a 1% 
Direct observation of thermally induced vortex depinning
Temperature between (0.1K‐2.1K)
144 images
8 min each one
Several images at each T
Physics Today, see youtube channel physics update
http://www.youtube.com/watch?v=7fgNpqgZWKY
http://www.youtube.com/user/citecnomik1
Vortex bundles with weak pinning at 100 mK
Increasing the field in steps
No time variation of flux distribution
Pinning produces spatial variation of B
Critical state
Campo Crítico Hc2 (T)
FL=‐FP
6
5
4
3
2
1
0
0
1
2
3
Temperatura (K)
33 STS images
0.04 T steps
4
FL  J  B
d
Vortex pinning
2
Ψ  ns
I
H

J
r

J
FL   FP  J c  B
RI/V
Itunnel
VI/V=108·Itunn
Pinning centers
• surface corrugation (L)
•…
Vbias
+
-
~ nA
Tip
+
SC
sample
> mA
R
Isamp
le
el
I/V
converter
Vbias + Vsample
+
-
Microscopic determination of the critical current
J = 0.8·105A/m2; H = 0.5T
J (A/m2)
T= 4K
J0 = 1.2·105 A/m2
0.8·105A/m2
T= 5K
J = 0.4·105A/m2; H = 0.5T
0.4·105A/m2
0A/m2
0.5T
H (T)
H0 = 4.1T
T = 4K
T = 5K
T = 6K
J = 0A/m2; H = 0.5T
T0 = 7.2K
T (K)
Tunnel current
I (VBias)
Bias
VBias
d
T = 4K
In plane current
Isample
Vortex motion
In plane current
T = 5K
T = 6K
LABORATORIO DE BAJAS TEMPERATURAS:
CERCA DEL CERO ABSOLUTO
 Tecnología del liquido
 Puntos fríos en el mK
 Superconductividad
 Microscopía de la superconductividad
 Future work :
 cryofree
 high magnetic fields
Future of cryogenic scanning probe microscopy
Compact design enabling
 Versatility (cryocooler)
 Extreme conditions: high magnetic fields and lower temperatures
Temperature in K
Spatial resolution in pm
LHe
10
LHe
10000
1000
1
100
Cryocooler
10
1
Superconducting
solenoid
Cryocooler
0.01
0.1
Resistive high field
magnet
Superconducting
solenoid
0.1
UHV + LHe
Resistive high field
magnet
UHV + LHe
Future of cryogenic scanning probe microscopy
Compact design enabling
 Versatility (cryocooler)
 Extreme conditions: high magnetic fields and lower temperatures
High magnetic fields are one of the most
powerful tools available to scientists for the
study, the modification and the control of the
state of matter. Europe should have a dedicated
world class magnet field laboratory (EMFL)
which provides the highest possible fields (both
continuous and pulsed) to its researchers
Campus CEI
 15 solenoides superconductores de > 8 T
 Campo magnético de 17 T
 Desarrollo y construcción de solenoides de 3 ejes
 UAM + CSIC + …
Cryogenic scanning probe microscopy
A. Maldonado, J.A. Galvis Echeverry, M.R. Osorio, R.F. Luccas, P. Kulkarni, V. Crespo
A. Buendía,
I. Guillamón, J.G. Rodrigo, S. Vieira
Laboratorio de Bajas Temperaturas
Dpto. Física de la Materia Condensada
Instituto de Ciencia de Materiales Nicolás Cabrera
Universidad Autónoma de Madrid (UAM)
J. Sesé, R. Córdoba, A. Fernández Pacheco, J.M. de Teresa, R. Ibarra
ICMA, Unizar, Instituto de Nanociencia de Aragón
F. Guinea
Instituto de Ciencia de Materiales de Madrid,
Consejo Superior de Investigaciones Científicas, Madrid
S. Bud’ko, P.C. Canfield
Ames Laboratory, Ames – USA
S. Bannerjee
IIT Kanpur – India
V. Tissen, Chernogolovka, Russia
T. Baturina, Novosibirsk, Russia, V. Vinokur, Argonne, USA
L. Cario, Nantes; P. Rodiere, P. Lejay, J.P. Brison, Dai Aoki, J. Flouquet
Institut Néel and SPSMS/DRFMC
E. Navarro Moratalla, C. Martí Gastaldo, E. Coronado, ICMol Valencia
Experimentos
LBTUAM
de demostración
DIFUSIÓN
http://www.youtube.com/user/citecnomik1/
Gracias por su atención
http://www.uam.es/citecnomik
http://www.uam.es/inc