Coexistence of Antiferromagnetism and Superconductivity near the Quantum Criticality in Heavy Fermion Compound CeRhIn$_5$

TL;DR

This study demonstrates the microscopic coexistence of antiferromagnetism and superconductivity in CeRhIn$_5$ under pressure, revealing their interplay near quantum criticality through NQR and Meissner effect measurements.

Contribution

It provides direct evidence of homogeneous coexistence of AFM and SC in CeRhIn$_5$ at a specific pressure, advancing understanding of quantum critical phenomena in heavy fermion systems.

Findings

AFM and SC coexist homogeneously at microscopic level

NQR spectrum split indicates magnetic order

Meissner signal confirms bulk superconductivity

Abstract

We report a study on the interplay between antiferromagnetism (AFM) and superconductivity (SC) in a heavy-fermion compound CeRhIn$_5$ under pressure $P=1.75$ GPa. The onset of the magnetic order is evidenced from a clear split of $^{115}$In-NQR spectrum due to the spontaneous internal field below the N\'eel temperature $T_N=2.5$ K. Simultaneously, bulk SC below $T_c=2.0$ K is demonstrated by the observation of the Meissner diamagnetism signal whose size is the same as in the exclusively superconducting phase. These results indicate that the AFM coexists homogeneously with the SC at a microscopic level.