Field-induced quantum critical point in the pressure-induced superconductor CeRhIn5

TL;DR

This study provides evidence for a field-induced quantum critical point in CeRhIn5 at pressure P2, where resistivity and specific heat behaviors indicate non-Fermi liquid properties and quantum criticality associated with superconductivity.

Contribution

It demonstrates the existence of a quantum critical point in CeRhIn5 under magnetic field at P2, linking quantum criticality with pressure-induced superconductivity.

Findings

Resistivity becomes sub-T-linear above Tc near P2.

The A coefficient diverges as Hc2 is approached.

Evidence of quantum critical behavior similar to CeCoIn5.

Abstract

When subjected to pressure, the prototypical heavy-fermion antiferromagnet CeRhIn5 becomes superconducting, forming a broad dome of superconductivity centered around 2.35 GPa (=P2) with maximal Tc of 2.3 K. Above the superconducting dome, the normal state shows strange metallic behaviours, including a divergence in the specific heat and a sub-T-linear electrical resistivity. The discovery of a field-induced magnetic phase that coexists with superconductivity for a range of pressures P < P2 has been interpreted as evidence for a quantum phase transition, which could explain the non-Fermi liquid behavior observed in the normal state. Here we report electrical resistivity measurements of CeRhIn5 under magnetic field at P2, where the resistivity is sub-T-linear for temperatures above Tc (or T_FL) and a T^2-coefficient A found below T_FL diverges as Hc2 is approached. These results are similar to the field-induced quantum critical compound CeCoIn5 and confirm the presence of a quantum critical point in the pressure-induced superconductor CeRhIn5.