Inhomogeneous Superconductivity in the
Heavy Fermion CeRhIn5
Tuson Park
Department of Physics, Sungkyunkwan University,
Suwon 440-746, South Korea
成 均 館 (since 1398)
IOP Workshop, Nov. 10-12, 2012
Collaborators
E. Park, S. Seo, S. Lee, D. Shin, S. Shin
: Sungkyunkwan Univ.
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.
H. Q. Yuan: Zhejiang University, China
V. Sidorov: HPPI, Russia
Z. Fisk: Univ. California - Irvine
I. Vekhter: Louisiana State Univ.
N. Curro: Univ. California - Davis.
R. R. Urbano: UNICAMP.
SKKU
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(unpublished)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
organics
Fe-based pnictides
heavy fermion
CeRhIn5
Non-Fermi liquid at optimal Tc
cuprate
Fe pnictides
Common threads
heavy fermion
100
Universial Class of SCs
0.6
CeRhIn
T 5
10
c (-cm)
organics
CeRhIn5
1
2
T
0.1
1
1 bar
22.7 kbar
52.6 kbar
10
100
Temperature (K)
temperature
Emergent phases near a quantum critical point
Quantum critical
matter (NFL)
Ordered
Ordered
state state
SC
Fermi
liquid
δc
temperature –control parameter (δ)
phase diagram
δ
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
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
Quantum critical superconductivity in CeRhIn5
100
I // ab-plane
2.3 K
20 K
50 K
280 K
ab
(P)
(P) // abab (5.2
(5.2 GPa)
GPa)
ab
80
60
40
20
0
0
1
2
3
4
5
P (GPa)
[100]
[010]
[100]
905
SC
900
C / T (a. u.)
Isothermal measurements of CeRhIn5 as
a fn of pressure: (P) /  (5.2 GPa)
Nature 456, 366 (2008)
1.8 K
& 0.5 T
895
330
328
326
Quantum fluctuations are the origin of the
unconventional superconductivity
0.3 K
& 0.5 T
324
0
90
180
angle ()
4-fold modulation in field-angle specific heat
PRL 101, 177002 (2008)
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)
ab (m cm)
Textured SC in high-Tc cuprates
10
-1
10
-2
10
-3
10
-4
La1.875Ba.125CuO4
bulk Tc
0
10
20
30
40
50
T (K)
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
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 mounted
Pb Tc as a meausre of pressure
CeRhIn5 in the coexisting phase
TN
12.0
TN
bulk Tc
6000
Tc onset
T (K)
C/T (arb. units)
4
2
AFM
10.0
P = 15.8 kbar
Ton
8.0
4000
6.0
4.0
2000
SC
2.0
AFM+ SC
0
0.0
0.5
1.0
1.5
2.0
2.5
P (GPa)
Phase diagram for better sample with
RRR ~ 1000
0
0.0
0
1
2
3
4
T (K)
Tc
Tc onset in the resistivity is different
from the bulk Tc determined by the
heat capacity
ab ( cm)
6
Pressure effects on the Tc difference
a
a
Tc onset
C/T (arb. units)
6000
bulk Tc
c
b
T (K)
4
0
0.0
1.0
2.0
3.0
0.0
4.0
1.5
2.0
2.5
P (GPa)
Tc difference between resistivity and
specific heat only in the coexisting
phase
Tc difference is not from disorder,
but from competing orders
10.0
P = 1.7 GPa
GPa
2000
5.0
0
0.0
1.0
2.0
3.0
ab ( cm)
1.0
4000
0.0
4.0
c
6000
10.0
P = 2.2 GPa
4000
5.0
2000
0
0.0
1.0
2.0
3.0
ab ( cm)
AFM+ SC
0.5
5.0
2000
b
SC
0
0.0
4000
AFM
C/T (arb. units)
2
10.0
P = 1.58 GPa
GPa
ab ( cm)
TN
C/T (arb. units)
6
0.0
4.0
T (K)
TP et al., Phys. Rev. Lett. 108, 077003 (2012)
Resistivity anisotropy in the SC transition regioin
6
TN
bulk Tc
Tc onset
10.00
10.00
T (K)

,, 
ab
cc ((
-cm)
-cm)
ab
4
1.00
1.00
(ab)
ab)
bar(J(J
////ab)
11bar
1.61
GPa
(ab)
// ab)
1 bar (J // c)(J
2.42 (J
GPa
// c)(ab)
1bar
1bar GPa
(c) (J // c)
1.65
1.65 GPa (c)
2.43 GPa (c)
0.10
0.10
cm
cm
90nn
(0)==90
c(0)
cc
2
AFM
SC
AFM+ SC
0
0.0
0.5
1.0
1.5
2.0
2.5
P (GPa)
cm
cm
7.9nn
(0)
(0)==7.9
ab
ab
ab
0.01
0.01
1.0
1.0
2.0
2.0
3.0
3.0
4.0
4.0
5.0
5.0
T(K)
T(K)
At 1bar, residual resistivity for J//c is larger
than J // ab by a factor of 10
Contradicting conventional expectation,
however, resistivity drops to zero immediately
for J // c, while it has a long tail for J // ab
Resistivity anisotropy only
in the coexisting phase
Textured SC state
Broad tail of SC transition in ρab is not
from heating effects.
Additional in-plane anisotropy
1.00
 ( cm)
1.00
P = 1.58 GPa
@ 0.1 mA
@ 10.0 mA
0.10
0.01
0.10
1.6
1.8
2.0
2.2
2.4
1.6
1.7
T (K)
2.2
I//100
I//110
3.0
2.0
1.0
T (K)
Tc, mid (K)
ab (-cm)
10.00
I//100
I//110
2.0
c
1.8
AF
SC
AF
SC
b
AF
a
1.3
1.4
1.5
P (GPa)
Recent neutron scattering in the coexisting phase of
CeRhIn5
4
Tc
TN
T (K)
3
AFM
2
SC
1
AFM+ SC
0
0.0
0.5
1.0
1.5
2.0
2.5
P (GPa)
T*Tcorresponds
to resistive T
c corresponds to the bulk Tc, cwhere
=>
& Q2 coexists, while Q1
QSC
2 completely replaces Q1 and
disappears
below
bulk Tc
coexists with
SC state
c
Q1
Neutron scattering of CeRhIn5 at 1.48 GPa
- Aso et al., JPSJ 78, 073703 (2009).
SC & Q1 SC & Q1
Q2
Q2
b
a
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?
c
Q1
SC & Q1 SC & Q1
Q2
Q2
b
a
Q1 = (0.5, 0.5, 0.326), Q2 = (0.5, 0.5, 0.391)
ab (m cm)
Textured SC in high-Tc cuprates
10
-1
10
-2
10
-3
10
-4
La1.875Ba.125CuO4
bulk Tc
0
10
20
30
40
50
T (K)
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
I. Martin & C. Panagopoulos, EPL
92, 67001 (2010)
Textured SC in organics
(TMTSF)2PF6
Pasquier et al.,
Physica B 407, 1806 (2012)
pressure
Textured SC in Fe pnictides
Fernandes et al.,
Phys. Rev. B 81, 140501 (2010)
Chu et al., Science 329, 824 (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!