Non-Fermi-liquid nature and exotic thermoelectric power in the heavy-fermion superconductor UBe13

Yusei Shimizu (1) , Alexandre Pourret (2) , Georg Knebel (2) , Alexandra Palacio-Morales (2) , Dai Aoki (2, 3)

1 Institute for Solid State Physics, University of Tokyo
2 IMAPEC - Instrumentation, Material and Correlated Electrons Physics
3 Tohoku University [Sendai]

We report quite exotic thermoelectric power S in UBe13. At 0 T, the negative S/T continues to strongly enhance down to the superconducting transition temperature with no Fermi-liquid behavior. vertical bar S/T vertical bar is dramatically suppressed and becomes rather modest with increasing field. We have also obtained precise field dependencies of (i) an anomaly in S due to an exotic Kondo effect and (ii) a field-induced anomaly in S/T associated with the anomalous upward H-c2(T). In contrast to the field-sensitive transport property, the normal-state specific heat is magnetically robust, indicating that the largeness of the 5f density of states remains in high fields. This unusual behavior in UBe13 can be explained by a considerable change in the energy derivative of the conduction-electron lifetime tau(c)(epsilon) at the Fermi level under magnetic fields.

Keywords: Low-Temperature Magnetoresistivity; High Magnetic-Fields; Phase-Diagram; Susceptibility; U1-xThxBe13; CeCu2Si2

Domains: Physics [physics]

Yusei Shimizu, Alexandre Pourret, Georg Knebel, Alexandra Palacio-Morales, Dai Aoki. Non-Fermi-liquid nature and exotic thermoelectric power in the heavy-fermion superconductor UBe13. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2015, 92 (24), pp.241101(R). ⟨10.1103/PhysRevB.92.241101⟩. ⟨cea-01735130⟩