Distinct domain switching in Nd0.05Ce0.95CoIn5 at low and high fields

TL;DR

This study investigates how magnetic domain populations in Nd0.05Ce0.95CoIn5 respond differently to magnetic field rotation across a quantum phase transition, revealing changes in electronic structure and spin susceptibility.

Contribution

It demonstrates distinct domain switching behaviors in low and high magnetic fields, indicating a change in electronic structure at the quantum phase transition.

Findings

Weak domain population change in low-field SDW phase

Sharp domain switch in high-field Q-phase near the a-axis

Electronic structure alteration at the quantum phase transition

Abstract

Nd0.05Ce0.95CoIn5 features a magnetic field-driven quantum phase transition that separates two antiferromagnetic phases with an identical magnetic structure inside the superconducting condensate. Using neutron diffraction we demonstrate that the population of the two magnetic domains in the two phases is affected differently by the rotation of the magnetic field in the tetragonal basal plane. In the low-field SDW-phase the domain population is only weakly affected while in the high-field Q-phase they undergo a sharp switch for fields around the a-axis. Our results provide evidence that the anisotropic spin susceptibility in both phases arises ultimately from spin-orbit interactions but are qualitatively different in the two phases. This provides evidence that the electronic structure is changed at the quantum phase transition, which yields a modified coupling between magnetism and superconductivity in the Q-phase.