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1
Phase states and phase transformations of CeMIn5
(MCo, Rh, Ir)
Makariy Tanatar University of Toronto
Louis Taillefer
Johnpierre Paglione Dave Hawthorn Etienne
Boaknin Mike Sutherland
Cedomir Petrovic Paul Canfield John Sarrao
Rob Hill Filip Ronning Shiyan Li
2
CeIn3
Tc?200 mK, Pc26 kbar
N.D.Mathur et al. Nature 394, 39 (1998)
Resistivity (??cm)
Ce
In
Simple AF Q111
??0AT1.6?0.2
3
G.Knebel et al. (2002)
Superconductivity near QCP mediated by magnetic
quantum fluctuations
unconventional SC
S.Kawasaki et al. (2002)
Experiment 119In NMR 26.5 kbar bulk Tc95
mK 1/T1 power law decrease T?0 SC gap with line
nodes
4
Qualitative similarity coincidence ?
High-Tc
For magnetic iteractions model
Tc? 3D?2D Tc? f?d

• Tc????exp(-(1?)/g?)
• ?- the bandwidth of ?q
• -ehancement of qp mass
• - incoherent inelastic scatterin
• ?- scattering on impurities

5
C.Petrovic et al. (2001)
CeMIn5 MRh, Ir, Co
001c
100
? (??cm)
Ce, La
Co, Rh, Ir In
3D?2D Tc? 0.1 to 2.3 K
Temperature
6
P.G.Pagliuso et al. (2002)
H.Hegger, et al. (2000)
21 kbar
7.9
0
7
Non-Fermi-liquid behavior
J.S.Kim , et al. (2002)
?(emu/mole)
Co
(Cmeas-Clatt)/T (J/K2mole)
?C/TlnT
Temperature
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Anisotropic superconducting gap in CeCoIn5
Heat capacity
R.Movshovich et al. PRL, 86, 5152 (01)
Thermal conductivity
R.Movshovich et al. PRL, 86, 5152 (01)
NMR relaxation rate
Y.Kohori et al. PRB 64, 134526(01)
G.-q. Zheng et al. PRL 86, 4664 (01)
Penetration depth
R.J.Ormeno et al. PRL 86, 5152 (01)
S.Ozcan et al. cond-mat/0206069
E.E.M.Chia et al. cond-mat/0206468
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Anisotropic superconducting gap in CeCoIn5
K.Izawa et al. PRL2002
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Gap function of CeCoIn5
Line node
Spin singlet
No broken time reversal symmetry
Nodes are located perpendicular to the
2D-plane along (p,p)-directions
dx -y
AF fluctuation plays an important role in the
superconductivity
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CeCoIn5 Superconductivity in the vicinity of
QCP Where the QCP is located? What kind of
transformation?
V.A.Sidorov et al. 2002
Fermi-liquid state is restored at high P
QCP at negative P?
12
CeRhIn5 coexistence of SC and AF
T.Mito et al. 2003
CeCoIn5
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Fermi-liquid state is restored with La doping and
in magnetic field
5T NFL
28.5T FL?
QCP with La doping?
Phase transition in magnetic field?
S.Nakatsuji et al. 2002
J.S.Kim , et al. (2002)
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CeCoIn5 nontrivial magnetoresistance
16 T FL?
0T NFL
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CeCoIn5 evolution of FL picture
upturn at high field?
orbital magnetoresistance in high field limit ???1
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H-T Phase Diagram of CeCoIn5

• onset of T2 resistivity

QCP
Critical restoration of FL QCP at Hc2? QCP at MR
crossover?

• change in sign of MR

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Compare CeIn3
QCP
G.Knebel et al. (2002)
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Compare YbRh2Si2
QCP
P.Gegenwart el et al. (2002)
19
CeCoIn5what pins QCP to Hc2?
Occasional coincidence of magnetic and
superconducting transitions? Hidden AF state
behind SC order? Superconductivity itself?
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CeCoIn5 first order transition at Hc2
50 mK dc magn.
T.Tayama et al. 2002
A.Bianchi et al. 2002
21
CeCoIn5 first order transition at Hc2. Normal
state effect?
110
001
100
T.P.Murphy et al. 2002
22
CONCLUSION CeCoIn5 at H0 close to AF QCP - NFL
behavior - Unconventional SC Field-tuned QCP
with HHc2 Metamagnetic crossover in
Magnetoresistance to high T? T Probable
relation to 1st transition at Hc2 Posters by
J.Paglione and M.A.Tanatar in the main meeting