Quantum criticality near the upper critical field of Ce2PdIn8

Abstract

We report low-temperature specific-heat measurements in magnetic fields up to 12 T applied parallel and perpendicular to the tetragonal c axis of the heavy fermion superconductor Ce2PdIn8. In contrast to its quasi-two-dimensional (2D) relative CeCoIn5, the system displays an almost isotropic upper critical field. While there is no indication for a high-field and low-temperature phase in Ce2PdIn8, the data suggest a smeared weak first-order superconducting transition close to H-c2 approximate to 2 T. The normal-state electronic specific-heat coefficient displays logarithmically divergent behavior, comparable to CeCoIn5 and in agreement with 2D quantum criticality of spin-density-wave type.