Mass Enhancement and Reentrant Ground State in Magnetic Field

TL;DR

This paper discusses reentrant ground states in heavy fermion systems under magnetic fields, highlighting the role of effective mass enhancement and phase transitions in URhGe, UGe2, and CeRhIn5.

Contribution

It provides a comparative analysis of magnetic field reentrant phases in three heavy fermion compounds, linking effective mass changes to reentrant phenomena.

Findings

URhGe shows reentrant superconductivity linked to spin reorientation.

UGe2 exhibits increased upper critical field at a ferromagnetic transition.

CeRhIn5 demonstrates reentrant antiferromagnetism under magnetic field.

Abstract

Three different cases of magnetic field reentrant ground states in heavy fermion systems, URhGe, UGe$_2$ and CeRhIn$_5$ recently studied in Grenoble, are discussed. URhGe is a ferromagnetic superconductor with reentrace of superconductivity under magnetic field ($H$) which is associated to the spin reorientation field. UGe$_2$ is a ferromagnetic superconductor with an enhancement of the upper critical field $H_{c2}$ of superconductivity at its metamagnetic transition between 2 ferromagnetic phases. CeRhIn$_5$ is a superconductor with $H$ reentrant antiferromagnetism. We analyze the links between the $H$ enhancement of the different contributions to the effective mass and the field reentrant phase.