Highly Mobile Carriers in a Candidate of Quasi-Two-Dimensional Topological Semimetal AuTe$_2$Br

TL;DR

This paper investigates the crystal and electronic structures of AuTe2Br, a quasi-2D topological semimetal candidate, revealing highly mobile carriers and large magnetoresistance due to its unique Fermi surface topology.

Contribution

It provides the first detailed analysis of AuTe2Br's electronic structure and transport properties, highlighting its high mobility and topological features.

Findings

High carrier mobility of 10^5 cm^2V^-1s^-1 at low temperature.

Observation of non-saturated, large magnetoresistance up to 3×10^5.

Presence of Dirac cone along the kz direction in the Fermi surface.

Abstract

We report the crystal and electronic structures of a non-centrosymmetric quasi-two-dimensional (2D), candidate of topological semimetal AuTe2Br. The Fermi surface of this layered compound consists of 2D-like, topological trivial electron and non-trivial hole pockets which host a Dirac cone along the kz direction. Our transport measurements on the single crystals show highly anisotropic, compensated low-density electrons and holes, both of which exhibit ultrahigh mobility at a level of 10^5cm^2V^-1s^-1 at low temperature. The highly mobile, compensated carriers lead a non-saturated, parabolic magnetoresistance as large as 3*10^5 in single-crystalline AuTe2Br in a magnetic field up to 58 T.