Inhomogeneous Superconductivity in the Heavy Fermion CeRhIn 5

1. 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

2. 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. SKKU 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.

3. 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 Lett. 108, 077003 (2012) • Disorder, magnetism, and superconductivity: • Cd-doped CeMIn5 (M=Co, Rh, Ir) • (unpublished)

4. Phase diagram of unconventional SCs cuprate Fe-based pnictides heavy fermion organics CeRhIn5

5. Non-Fermi liquid at optimal Tc cuprate Fe pnictides Common threads heavy fermion organics Universial Class of SCs CeRhIn5

6. Emergent phases near a quantum critical point temperature Ordered state δc δ temperature –control parameter (δ) phase diagram Quantum critical matter (NFL) Ordered state P. Coleman & A. J. Schofield, Nature 433 ('05) Fermi liquid Quantum phase transition is a transition between ordered and disordered states driven by quantum fluctuations at T = 0 K SC • 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

7. Quantum critical superconductivity in CeRhIn5 SC Isothermal measurements of CeRhIn5 as a fn of pressure: r(P) / r (5.2 GPa) Nature 456, 366 (2008) Quantum fluctuations are the origin of the unconventional superconductivity 4-fold modulation in field-angle specific heat PRL 101, 177002 (2008)

8. 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 Lett. 108, 077003 (2012) • Disorder, magnetism, and superconductivity: • Cd-doped CeMIn5 (M=Co, Rh, Ir) • (unpublished)

9. Textured SC in high-Tc cuprates Q. Li et al., PRL 99, 067001 (2007) Y. Ando et al., PRL 92, 247004 (2004)  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)

10. 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))

11. Experiments: simultaneous measurements of heat capacity and resistivity under pressure Plug with samples mounted Pb Tc as a meausre of pressure Hybrid clamp-type pressure cell (up to 3 GPa) with silicone as transmitting medium

12. CeRhIn5 in the coexisting phase TN Ton Phase diagram for better sample with RRR ~ 1000 Tc Tc onset in the resistivity is different from the bulk Tc determined by the heat capacity

13. Pressure effects on the Tc difference a c b Tc difference between resistivity and specific heat only in the coexisting phase Tc difference is not from disorder, but from competing orders TP et al., Phys. Rev. Lett. 108, 077003 (2012)

14. Resistivity anisotropy in the SC transition regioin 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

15. Textured SC state Broad tail of SC transition in ρabis not from heating effects. Additional in-plane anisotropy c SC AF AF b SC AF a

16. Recent neutron scattering in the coexisting phase of CeRhIn5 c SC & Q2 Q1 Q1 b SC & Q2 Q1 a T* corresponds to resistive Tc => SC & Q2 coexists, while Q1 disappears below bulk Tc Tc corresponds to the bulk Tc, where Q2 completely replaces Q1 and coexists with SC state Neutron scattering of CeRhIn5 at 1.48 GPa - Aso et al., JPSJ 78, 073703 (2009). Q1 = (0.5, 0.5, 0.326), Q2 = (0.5, 0.5, 0.391)

17. 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 c SC & Q2 Q1 Q1 • Presence of competing phase & proximity to a QCP are keys to the textured SC phase • Is textuerd SC unique in CeRhIn5? b SC & Q2 Q1 a Q1 = (0.5, 0.5, 0.326), Q2 = (0.5, 0.5, 0.391)

18. Textured SC in high-Tc cuprates 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)

19. Textured SC in organics (TMTSF)2PF6 Pasquier et al., Physica B 407, 1806 (2012) pressure

20. Textured SC in Fe pnictides Fernandes et al., Phys. Rev. B 81, 140501 (2010) Chu et al., Science 329, 824 (2010) (arXiv:1112.2243v1)

21. 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

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