Post on 14-Jan-2016
Inhomogeneous Superconductivity in the Heavy Fermion CeRhIn5
Tuson Park
Department of Physics, Sungkyunkwan University, Suwon 440-746, South Korea
IOP Workshop, Nov. 10-12, 2012
成 均 館 (since 1398)
Collaborators
H. Q. Yuan: Zhejiang University, China
X. Lu, H. Lee, F. Ronning, E. D. Bauer, R. Movshovich, J. L. Sarrao, I. Martin, Z. Zhu, J. D. Thompson: Los Alamos National Lab.
E. Park, S. Seo, S. Lee, D. Shin, S. Shin: Sungkyunkwan Univ.
V. Sidorov: HPPI, Russia
SKKU
Z. Fisk: Univ. California - Irvine
I. Vekhter: Louisiana State Univ.
N. Curro: Univ. California - Davis.
R. R. Urbano: UNICAMP.
Outline
Quantum criticality and superconductivity
Inhomogeneous SC state in the quantum critical superconductor CeRhIn5
- Phys. Rev. Lett. 108, 077003 (2012)
Disorder, magnetism, and superconductivity: Cd-doped CeMIn5 (M=Co, Rh, Ir) (unpublished)
Phase diagram of unconventional SCs
cuprate Fe-based pnictides
organics heavy fermion
CeRhIn5
Non-Fermi liquid at optimal Tc
cuprate Fe pnictides
organics heavy fermion
CeRhIn5
1 10 100
0.1
1
10
100
CeRhIn5
T2 1 bar 22.7 kbar 52.6 kbar
c (
-c
m)
Temperature (K)
T0.6
Common threads
Universial Class of SCs
Emergent phases near a quantum critical point
P. Coleman & A. J. Schofield, Nature 433 ('05)
Quantum phase transition is a transition between ordered and disordered states
driven by quantum fluctuations at T = 0 K
Ordered state
δc
tem
pera
ture
δ
temperature –control parameter (δ) phase diagram
Orderedstate
Fermi liquid
Quantum critical matter (NFL)
Breakdown of Fermi liquid: Δρ Tn (n <2), C/T log T0/T
Continuous source of new emergent states: unconventional superconductivity, metamagnetism (Sr3Ru2O7), stripes in the cuprates, nematic states in URu2Si2 & Fe-based SCs
SC
SC
Isothermal measurements of CeRhIn5 as a fn of pressure: (P)(5.2 GPa)
Nature 456, 366 (2008)
Quantum critical superconductivity in CeRhIn5
0 1 2 3 4 50
20
40
60
80
100
ab(P
) /
ab (
5.2
GP
a)
P (GPa)
I // ab-plane 2.3 K 20 K 50 K 280 K
0 90 180
324
326
328
330
895
900
905[100]
0.3 K& 0.5 T
1.8 K& 0.5 T
[100]
C /
T (
a. u
.)
angle ()
[010]
4-fold modulation in field-angle specific heatPRL 101, 177002 (2008)
0 1 2 3 4 50
20
40
60
80
100
ab(P
) /
ab (
5.2
GP
a)
P (GPa)
I // ab-plane 2.3 K 20 K 50 K 280 K
Quantum fluctuations are the origin of the unconventional superconductivity
Outline
Quantum criticality and superconductivity
Inhomogeneous SC state in the quantum critical superconductor CeRhIn5
- Phys. Rev. Lett. 108, 077003 (2012)
Disorder, magnetism, and superconductivity: Cd-doped CeMIn5 (M=Co, Rh, Ir) (unpublished)
0 10 20 30 40 50
10-4
10-3
10-2
10-1
ab
(m
cm
)
T (K)
La1.875
Ba.125
CuO4
bulk Tc
Q. Li et al., PRL 99, 067001 (2007)
resistive transition far above bulk Tc
Broad tail below the Tc onset temperature for transition in c < ab
Textured SC in high-Tc cuprates
I. Martin & C. Panagopoulos, EPL 92, 67001 (2010)
Y. Ando et al., PRL 92, 247004 (2004)
Filamentary superconductivity in CeRhIn5
Filamentary superconductivity due to bad sample quality?
Manifestation of a new state of matter in the vicinity of a QCP?
Tc difference below 1.9 Gpa (Knebel et al., JPCM 16, 8905 (2004))
Experiments: simultaneous measurements of heat capacity and resistivity under pressure
Hybrid clamp-type pressure cell(up to 3 GPa) with silicone as transmitting medium
Plug with samples mountedPb Tc as a meausre of pressure
CeRhIn5 in the coexisting phase
0 1 2 3 40
2000
4000
6000
0.0
2.0
4.0
6.0
8.0
10.0
12.0
C/T
(ar
b. u
nits
)
T (K)
ab (
cm
)
P = 15.8 kbar
TN
Tc
Ton
Tc onset in the resistivity is different from the bulk Tc determined by the heat capacity
0.0 0.5 1.0 1.5 2.0 2.50
2
4
6 TN
bulk Tc
Tc onset
SC
AFM+ SC
AFM
T (
K)
P (GPa)
Phase diagram for better sample with RRR ~ 1000
Pressure effects on the Tc difference
0.0 1.0 2.0 3.0 4.00
2000
4000
6000
0.0
5.0
10.0
a
C/T
(ar
b. u
nits
)
ab (
cm
)
P = 1.58 GPa
0.0 0.5 1.0 1.5 2.0 2.50
2
4
6 TN
bulk Tc
Tc onset
SC
AFM+ SC
AFM
T (
K)
P (GPa)
Tc difference between resistivity and specific heat only in the coexisting phase
TP et al., Phys. Rev. Lett. 108, 077003 (2012)
0.0 1.0 2.0 3.0 4.00
2000
4000
6000
0.0
5.0
10.0
0.0 1.0 2.0 3.0 4.00
2000
4000
0.0
5.0
10.0
a
C/T
(ar
b. u
nits
)
b
ab (
cm
)
P = 1.58 GPa
P = 1.7 GPa
C/T
(ar
b. u
nits
)
ab (
cm
)
0.0 1.0 2.0 3.0 4.00
2000
4000
6000
0.0
5.0
10.0
0.0 1.0 2.0 3.0 4.00
2000
4000
6000
0.0
5.0
10.0
0.0 1.0 2.0 3.0 4.00
2000
4000
0.0
5.0
10.0
P = 2.2 GPa
C/T
(ar
b. u
nits
)
T (K)
ab (
cm
)
a
c
C/T
(ar
b. u
nits
)
b
ab (
cm
)
P = 1.58 GPa
P = 1.7 GPa
C/T
(ar
b. u
nits
)
ab (
cm
)
ab c
Tc difference is not from disorder, but from competing orders
Resistivity anisotropy in the SC transition regioin
At 1bar, residual resistivity for J//c is larger than J // ab by a factor of 10Contradicting conventional expectation, however, resistivity drops to zero immediately for J // c, while it has a long tail for J // ab
1.0 2.0 3.0 4.0 5.00.01
0.10
1.00
10.00
ab,
c (
-cm
)
T(K)
1 bar (J // ab) 1 bar (J // c)
c(0) = 90 n cm
ab
(0) = 7.9 n cm
1.0 2.0 3.0 4.0 5.00.01
0.10
1.00
10.00
ab,
c (
-cm
)
T(K)
1 bar (J // ab) 1.61 GPa (J // ab) 1bar (J // c) 1.65 GPa (J // c)
c(0) = 90 n cm
ab
(0) = 7.9 n cm
1.0 2.0 3.0 4.0 5.00.01
0.10
1.00
10.00
ab,
c (
-cm
)
T(K)
1 bar (ab) 1.61 GPa (ab) 2.42 GPa (ab) 1bar (c) 1.65 GPa (c) 2.43 GPa (c)
c(0) = 90 n cm
ab
(0) = 7.9 n cm
0.0 0.5 1.0 1.5 2.0 2.50
2
4
6 TN
bulk Tc
Tc onset
SC
AFM+ SC
AFM
T (K
)
P (GPa)
Textured SC state
1.0 2.0 3.0
0.10
1.00
10.00
ab (
-cm
)
P = 1.58 GPa @ 0.1 mA @ 10.0 mA
T (K)
Broad tail of SC transition in ρab is not from heating effects.
1.6 1.8 2.0 2.2 2.4
0.01
0.10
1.00 I//100 I//110
(
cm)
T (K)
1.3 1.4 1.5 1.6 1.7
1.8
2.0
2.2
I//100 I//110
Tc,
mid (
K)
P (GPa)
Additional in-plane anisotropy
SCAF
SC b
c
a
AFAF
Recent neutron scattering in the coexisting phase of CeRhIn5
Neutron scattering of CeRhIn5 at 1.48 GPa- Aso et al., JPSJ 78, 073703 (2009).
Tc corresponds to the bulk Tc, where Q2 completely replaces Q1 and coexists with SC state
0.0 0.5 1.0 1.5 2.0 2.50
1
2
3
4 T
c
TN
SC
AFM+ SC
AFM
T (
K)
P (GPa)
T* corresponds to resistive Tc
=> SC & Q2 coexists, while Q1 disappears below bulk Tc
SC & Q2
Q1
SC & Q2
b
c
a
Q1Q1
Q1 = (0.5, 0.5, 0.326), Q2 = (0.5, 0.5, 0.391)
Summary & Discussion I
Discovery of a textured SC phase in the heavy fermion compound CeRhIn5:
- Tc difference- Resistivity anisotropy among different crystalline axes- Coincidence of Q2 onset with Tc onset
Presence of competing phase & proximity to a QCP are keys to the textured SC phase
Is textuerd SC unique in CeRhIn5?
SC & Q2
Q1
SC & Q2
b
c
a
Q1Q1
Q1 = (0.5, 0.5, 0.326), Q2 = (0.5, 0.5, 0.391)
0 10 20 30 40 50
10-4
10-3
10-2
10-1
ab
(m
cm
)
T (K)
La1.875
Ba.125
CuO4
bulk Tc
Q. Li et al., PRL 99, 067001 (2007)
resistive transition far above bulk Tc
Broad tail below the Tc onset temperature for transition in c < ab
Textured SC in high-Tc cuprates
I. Martin & C. Panagopoulos, EPL 92, 67001 (2010)
Textured SC in organics
(TMTSF)2PF6
pressure
Pasquier et al., Physica B 407, 1806 (2012)
Textured SC in Fe pnictides
Chu et al., Science 329, 824 (2010)Fernandes et al.,Phys. Rev. B 81, 140501 (2010)
(arXiv:1112.2243v1)
Perspective on textured state
Quantum critical SCs seem susceptible to new electronic states
Electrons spontaneously adjust themselves to minimize the stress coming from frustration among competing phases
Is textured SC state universal? Most likely
Add one more common thread to the unconventional SCs
Is it beneficial to superconductivity? Probably not in CeRhIn5
Thank you !감사합니다 !