Ambient-pressure bulk superconductivity deep in the magnetic state of CeRhIn5

TL;DR

This study reports the discovery of bulk superconductivity at ambient pressure in CeRhIn5 occurring deep within its magnetic state, characterized by specific heat, magnetic susceptibility, and electrical transport measurements at ultra-low temperatures.

Contribution

It provides evidence of a bulk superconducting phase transition at 110 mK in CeRhIn5 under ambient pressure, deep within its antiferromagnetic state, expanding understanding of coexistence of magnetism and superconductivity.

Findings

Superconductivity observed at T_c=110 mK

Transition occurs below antiferromagnetic temperature T_N=3.8 K

Significant portion of electronic states involved in transition

Abstract

Specific heat, magnetic susceptibility and electrical transport measurements were performed at ambient pressure on high-quality single crystal specimens of CeRhIn5 down to ultra-low temperatures. We report signatures of an anomaly observed in all measured quantities consistent with a bulk phase transition to a superconducting state at T_c=110 mK. Occurring far below the onset of antiferromagnetism at T_N=3.8 K, this transition appears to involve a significant portion of the available low-temperature density of electronic states, exhibiting an entropy change in line with that found in other members of the 115 family of superconductors tuned away from quantum criticality.