Quantum interference between quasi-2D Fermi surface sheets in UTe2

TL;DR

This study reveals that UTe2 has a simple Fermi surface composed of two quasi-2D cylindrical sections, demonstrated through quantum interference effects in high-field magnetoconductance measurements, impacting understanding of its topological superconductivity.

Contribution

The paper provides the first evidence of quantum interference effects in UTe2's magnetoconductance, supporting a quasi-2D Fermi surface model based on quantum oscillation data.

Findings

Observation of quantum interference in UTe2's magnetoconductance.

Confirmation of a quasi-2D Fermi surface structure.

Consistency with prior dHvA measurements.

Abstract

UTe$_2$ is a spin-triplet superconductor candidate for which high quality samples with long mean free paths have recently become available, enabling quantum oscillation measurements to probe its Fermi surface and effective carrier masses. It has recently been reported that UTe$_2$ possesses a 3D Fermi surface component [Phys. Rev. Lett. 131, 036501 (2023)]. The distinction between 2D and 3D Fermi surface sections in triplet superconductors can have important implications regarding the topological properties of the superconductivity. Here we report the observation of oscillatory components in the magnetoconductance of UTe$_2$ at high magnetic fields. We find that these oscillations are well described by quantum interference between quasiparticles traversing semiclassical trajectories spanning magnetic breakdown networks. Our observations are consistent with a quasi-2D model of this material's Fermi surface based on prior dHvA-effect measurements. Our results strongly indicate that UTe$_2$ -- which exhibits a multitude of complex physical phenomena -- possesses a remarkably simple Fermi surface consisting exclusively of two quasi-2D cylindrical sections.