Coexistence of antiferromagnetism and superconductivity in CeRhIn5 under high pressure and magnetic field

TL;DR

This study investigates the coexistence and interplay of antiferromagnetism and superconductivity in CeRhIn5 under high pressure and magnetic field, revealing complex phase transitions and re-entrant magnetic order.

Contribution

It provides detailed experimental insights into how magnetic field and pressure influence the coexistence of antiferromagnetism and superconductivity in CeRhIn5, highlighting a field-induced re-entrance of magnetic order.

Findings

Antiferromagnetic order vanishes near 2 GPa due to a first order transition.

Superconductivity appears above 1.5 GPa within the magnetic phase.

Magnetic field induces a transition inside the superconducting state, re-entrant antiferromagnetism.

Abstract

We report on detailed ac calorimetry measurements under high pressure and magnetic field of CeRhIn5. Under hydrostatic pressure the antiferromagnetic order vanishes near p_c*=2 GPa due to a first order transition. Superconductivity is found for pressures above 1.5 GPa inside the magnetic ordered phase. However, the superconductivity differ from the pure homogeneous superconducting ground state above 2 GPa. The application of an external magnetic field H || ab induces a transition inside the superconducting state above pc* which is strongly related to the re-entrance of the antiferromagnetism with field. This field-induced supplementary state vanishes above the quantum critical point in this system. The analogy to CeCoIn5 is discussed.