Intrinsic Anomalous Thermal Hall Effect in the Unconventional Superconductor UTe2

TL;DR

This paper explores the intrinsic anomalous thermal Hall effect in UTe2, a candidate spin-triplet superconductor, to probe its unconventional pairing states and identify symmetry-breaking features related to Weyl point nodes.

Contribution

It provides a comprehensive calculation of the anomalous thermal Hall conductivity for various non-unitary pairing states and Fermi surface geometries in UTe2, revealing potential signatures of its pairing symmetry.

Findings

Nonzero anomalous thermal Hall conductivity identified in specific pairing states.

Dependence of Hall conductivity on Fermi surface shape and pairing symmetry.

Potential use of thermal Hall measurements to determine pairing states in UTe2.

Abstract

We investigate the intrinsic anomalous thermal Hall effect as an effective probe of the order parameters of non-unitary pairing states of the putative spin-triplet superconductor UTe$_2$. We consider all symmetry-allowed non-unitary states under magnetic fields comprehensively, and calculate the anomalous Hall conductivity arising from time-reversal symmetry-breaking Weyl point nodes of the gap functions, assuming three types of Fermi surfaces; ellipsoid-shaped, cylinder-shaped, and ring-shaped ones, which are predicted by previous band calculations. We find the nonzero anomalous thermal Hall conductivity in the certain ratio of the two irreducible representations. The results may be utilized for future exploration of pairing states of UTe$_2$.