We present different transport measurements up to fields of 29~T in the recently discovered heavy-fermion superconductor UTe2 with magnetic field H applied along the easy magnetization a-axis of the body-centered orthorhombic structure. The thermoelectric power varies linearly with temperature above the superconducting transition, TSC=1.5 K, indicating that superconductivity develops in a Fermi liquid regime. As a function of field the thermolelectric power shows successive anomalies which are attributed to field-induced Fermi surface instabilities. These Fermi-surface instabilities appear at critical values of the magnetic polarization. Remarkably, the lowest magnetic field instability for H∥a occurs for the same critical value of the magnetization (0.4 μB) than the first order metamagnetic transition at 35~T for field applied along the b-axis. The estimated number of charge carriers at low temperature reveals a metallic ground state distinct from LDA calculations indicating that strong electronic correlations are a major issue in this compound.
@article{arxiv.1907.11118,
title = {Fermi-Surface Instabilities in the Heavy-Fermion Superconductor UTe2},
author = {Qun Niu and Georg Knebel and Daniel Braithwaite and Dai Aoki and Gérard Lapertot and Gabriel Seyfarth and Jean-Pascal Brison and Jacques Flouquet and Alexandre Pourret},
journal= {arXiv preprint arXiv:1907.11118},
year = {2020}
}