Superconducting Gap of UCoGe probed by Thermal Transport

TL;DR

This study investigates the superconducting gap structure of UCoGe using thermal conductivity measurements at very low temperatures and under magnetic fields, revealing multigap superconductivity and clarifying the nature of the gap in ferromagnetic superconductors.

Contribution

It provides experimental evidence for multigap superconductivity in UCoGe and clarifies the nature of its superconducting gap, addressing previous ambiguities.

Findings

Confirmed multigap superconductivity in UCoGe

Disentangled intrinsic and extrinsic effects in thermal transport

Provided evidence against partially gapped Fermi surfaces

Abstract

Thermal conductivity measurements in the superconducting state of the ferromagnet UCoGe were performed at very low temperatures and under magnetic field on samples of different qualities and with the heat current along the three crystallographic axis. This allows to disentangle intrinsic and extrinsic effects, confirm the situation of multigap superconductivity and shed new light on the situation expected or claimed for the gap in these ferromagnetic superconductors, like evidences of absence of "partially gapped" Fermi surfaces.