Heavy holes: precursor to superconductivity in antiferromagnetic CeIn3

TL;DR

This study uses quantum oscillation measurements to reveal heavy f-electron pockets in CeIn3, showing effective mass divergence before the antiferromagnetic critical point, which may explain the emergence of superconductivity from antiferromagnetic states.

Contribution

It provides the first detailed electronic structure analysis of CeIn3 at ambient pressure, linking heavy f-electron pockets to the onset of superconductivity in antiferromagnetic materials.

Findings

Heavy f-electron pockets are identified in CeIn3.

Effective mass divergence occurs before the antiferromagnetic critical field.

Fermi surface features may explain Cooper pair formation in antiferromagnetic states.

Abstract

Numerous phenomenological parallels have been drawn between f- and d- electron systems in an attempt to understand their display of unconventional superconductivity. The microscopics of how electrons evolve from participation in large moment antiferromagnetism to superconductivity in these systems, however, remains a mystery. Knowing the origin of Cooper paired electrons in momentum space is a crucial prerequisite for understanding the pairing mechanism. Of especial interest are pressure-induced superconductors CeIn3 and CeRhIn5 in which disparate magnetic and superconducting orders apparently coexist - arising from within the same f-electron degrees of freedom. Here we present ambient pressure quantum oscillation measurements on CeIn3 that crucially identify the electronic structure - potentially similar to high temperature superconductors. Heavy pockets of f-character are revealed in CeIn3, undergoing an unexpected effective mass divergence well before the antiferromagnetic critical field. We thus uncover the softening of a branch of quasiparticle excitations located away from the traditional spin-fluctuation dominated antiferromagnetic quantum critical point. The observed Fermi surface of dispersive f-electrons in CeIn3 could potentially explain the emergence of Cooper pairs from within a strong moment antiferromagnet.