inhomogeneous electronic states in superconductors ( chapelier , ioffe )
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discussion-session. Inhomogeneous electronic states in superconductors ( Chapelier , Ioffe ) How to disentangle the unavoidable atomic level inhomogeneity of real materials from the electronic inhomogeneity. Very Low Temperature STM: - PowerPoint PPT PresentationTRANSCRIPT
Inhomogeneous electronic states in superconductors (Chapelier, Ioffe)How to disentangle the unavoidable atomic level inhomogeneity of real materials from the electronic inhomogeneity
discussion-session
Maud VinetWalter EscoffierBenjamin SacépéThomas DubouchetCharlène Tonnoir
Claude ChapelierCEA INAC-SPSMS-LaTEQS, Grenoble
Very Low Temperature STM: a powerful probe for inhomogeneous superconducting states (tutorial)
Very Low Temperature STM: a powerful probe for inhomogeneous superconducting states (tutorial)
I. STM/STS and usual inhomogeneous superconducting states
II. Highly disordered superconductorsIII. Discussion
Coarse approach motor
Coarse positioning X-Y table
Sample holderTipPiezo tube10
cm
Scanning Tunneling Microscopy
Michael Schmid, TU Wien
P.Mallet et al., J. Vac. Sci. Technol. B 14, 1070 (1996) Michael Schmid, TU Wien
NbSe2
Scanning Tunneling Microscopy
P.Mallet et al., J. Vac. Sci. Technol. B 14, 1070 (1996)
D. Roditchev’s group, http://ln-www.insp.upmc.fr/
Michael Schmid, TU Wien
NbSe2
Scanning Tunneling Microscopy
Scanning Tunneling Spectroscopy
P.Mallet et al., J. Vac. Sci. Technol. B 14, 1070 (1996)
I
V
dI/dV
VeVfNd
dVdIVG T
S)()()(
NbSe2
D. Roditchev’s group, http://ln-www.insp.upmc.fr/
Scanning Tunneling Spectroscopy
P.Mallet et al., J. Vac. Sci. Technol. B 14, 1070 (1996)
I
V
dI/dV
VeVfNd
dVdIVG T
S)()()(
NbSe2
D. Roditchev’s group, http://ln-www.insp.upmc.fr/H. Hess et al., Physica B 169, 422 (1991)
I
V
dI/dV
Scanning Tunneling Spectroscopy
P.Mallet et al., J. Vac. Sci. Technol. B 14, 1070 (1996)
VeVfNd
dVdIVG T
S)()()(
NbSe2
D. Roditchev’s group, http://ln-www.insp.upmc.fr/H. Hess et al., Physica B 169, 422 (1991)
I
V
dI/dV
Scanning Tunneling Spectroscopy
P.Mallet et al., J. Vac. Sci. Technol. B 14, 1070 (1996)
VeVfNd
dVdIVG T
S)()()(
NbSe2
D. Roditchev’s group, http://ln-www.insp.upmc.fr/I. Guillamon et al., Phys. Rev.B 77, 134405 (2008)
http://www.oettinger-physics.de/
VortexNbSe2
Sachdev & Zhang, Science
http://www.oettinger-physics.de/
Vortex
H. Hess et al., Phys. Rev. Lett. . 62, 214 (1989)
NbSe2
http://www.oettinger-physics.de/
Vortex
H. Hess et al., Phys. Rev. Lett. . 62, 214 (1989)
NbSe2
http://www.oettinger-physics.de/
VortexNbSe2
H. Hess et al., Physica B 169, 422 (1991)
http://www.oettinger-physics.de/
Vortex
H. Hess et al., Physica B 169, 422 (1991)
Ch. Renner et al., Phys. Rev. Lett. (1991)
Nb1-x TaxSe2
http://www.oettinger-physics.de/
Vortex
J.E. Hoffman., Science 295, 466 (2002)
Bi2Sr2CaCu2O8+
Hybrid nanostructures
N. Moussy et al., Europhys. Lett. 55, 861 (2001)
M. Vinet et al., Phys. Rev. B 63, 165420 (2001)
-4 -2 0 2 4
0,5
1,0
1,5
dI/d
V (n
orm
aliz
ed)
V [mV]
195 nm
75 nm
12 nm
H. Le Sueur et al., Phys. Rev. Lett. 100, 197002 (2008)
Very Low Temperature STM: a powerful probe for inhomogeneous superconducting states (tutorial)
Superconductor-Insulator Transition
Granular systems Homogeneously disordered materials
H.M. Jaeger, et al., Phys. Rev. B 34, 14920 (1986)
D.B. Haviland, et al., Phys. Rev. Lett. 62, 2180 (1989)
GalliumBismuth
Superconductor-Insulator TransitionTiNReactive sputter deposition of TiN films
Homogeneously disordered ?
N. Hadaceket al., Phys. Rev. B 69, 024505 (2004)
100 nm
10 nm
Superconductor-Insulator TransitionTiN
100 nm
10 nm
T (K)
R (O
hms)
Reactive sputter deposition of TiN films
Granular ?Homogeneously disordered ?
N. Hadaceket al., Phys. Rev. B 69, 024505 (2004)
Superconductor-Insulator TransitionTiN
T (K)
R (O
hms)
Reactive sputter deposition of TiN films
Granular ?Homogeneously disordered ?
N. Hadaceket al., Phys. Rev. B 69, 024505 (2004)
≈ 80 × 80 × 2 nm
≈ 400
× 4
00 ×
3
nmW. Escoffier et al.,Phys. Rev. Lett. 93, 217005 (2004)
100 nm
10 nm
Superconductor-Insulator TransitionTiNReactive sputter deposition of TiN films
Homogeneously disordered ?
N. Hadaceket al., Phys. Rev. B 69, 024505 (2004)
≈ 80 × 80 × 2 nm
≈ 400
× 4
00 ×
3
nmW. Escoffier et al.,Phys. Rev. Lett. 93, 217005 (2004)
100 nm
10 nm
M. Baklanov and A. Satta (IMEC)
Superconductor-Insulator TransitionTiNAtomic layer deposition of 5 nm thick TiN films
-1,0 -0,5 0,0 0,5 1,00,0
0,5
1,0
1,5
2,0
G(V
), no
rmal
ized
V [mV]
= 260 µeVTeff = 0,25 K
-1,0 -0,5 0,0 0,5 1,00,0
0,5
1,0
1,5
2,0
= 225 µeVTeff = 0,32 K
G(V
), no
rmal
ized
V [mV]
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,00
1
2
3
4
5
6
7
8
R [k
]
T [K]
TiN 1 TiN 2 TiN 3
-1,0 -0,5 0,0 0,5 1,00,0
0,5
1,0
1,5
2,0
= 154 µeVTeff = 0,35 K
G(V
), no
rmal
ized
V [mV]
Increasing disorder
Superconductor-Insulator transition
Sacépé et al., Phys. Rev. Lett. 101, 157006 (2008)
TiN
Superconductor-Insulator transitionTiN
λ
Sacépé et al., Phys. Rev. Lett. 101, 157006 (2008)
Tc [K] Δ/TcVar.
[%]
4.7 1.8 ---1.3 2.3 121 2.6 20
0.45 4 50
A. Ghosal, M. Randeria, N. Trivedi, Phys. Rev. Lett. 81, 3940, (1998)Phys. Rev. B 65, 014501 (2001)
M. Ma and P.A. Lee, Phys. Rev. B 32, 5658, (1985)A. Kapitulnik, G. Kotliar, Phys. Rev. Lett. 54, 473, (1985)M. Feigel’man et al., Phys. Rev. Lett. 98, 027001, (2007)M. Feigel’man et al., Ann. Phys. 325, 1390 (2010)M. A. Skvortsov et al., Phys. Rev. Lett. 95,057002, (2005)
Pseudogap
B. Sacépé, et al., Nature Communications 1:140 (2010)
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,00
1
2
3
4
5
6
7
8
R [k
]
T [K]
TiN 1 TiN 2 TiN 3
Superconducting fluctuations correction to the DOSShort-lived Cooper pairs above Tc
A. Varlamov and V. Dorin, Sov. Phys. JETP 57, 1089, (1983)
Pseudogap
B. Sacépé, et al., Nature Communications 1:140 (2010)
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,00
1
2
3
4
5
6
7
8
R [k
]
T [K]
TiN 1 TiN 2 TiN 3
Superconducting fluctuations correction to the DOSShort-lived Cooper pairs above Tc
A. Varlamov and V. Dorin, Sov. Phys. JETP 57, 1089, (1983)
Pseudogap
B. Sacépé, et al., Nature Communications 1:140 (2010)
R□
[kΩ]Tc (R□) [K]
Tc (DOS)
[K]
3.5 1.31.3 1.271.27
4.3 1.01.0 0.980.98
7.4 0.450.45 0.450.45
An extreme sensitivity to Tc
Very Low Temperature STM: a powerful probe for inhomogeneous superconducting states (tutorial)
How to disentangle the unavoidable atomic level inhomogeneity of real materials from the electronic inhomogeneity ?
Which inhomogeneities ?
Down to which scale a real material must be considered granular or not ?
What is a homogeneously disordered material ?
How can we relate global macroscopic behavior (transport) and local signatures (STS) ?
Dilution fridge setup
Anomalous proximity effectSuperconducting granular TiN films
-1,5 -1,0 -0,5 0,0 0,5 1,0 1,50,0
0,5
1,0
1,5
2,0
2,5
3,0 xexp
= 0 nm x
cal = 0 nm
xexp
= 12 nm x
cal = 9 nm
xexp
= 20 nm x
cal = 21 nm
xexp
= 32 nm x
cal = 31 nmdI
/dV
E (meV)
dS,N
W. Escoffier et al., Phys. Rev. Lett. (2004)
≈ 80 × 80 × 2 nm
≈ 400
× 4
00 ×
3
nm
Theory : Zhang & Xiong,
Physica C (2006)
Anomalous proximity effectSuperconducting granular TiN films
B. Sacépé (unpublished)
1500 nm x 1500 nm
Superconducting fluctuations quantum corrections
Tc [K]
1.31
0.45
One parameter fit : Tc
Superconducting fluctuations quantum corrections