Magnetotransport properties of the type II Weyl semimetal candidate Ta3S2

TL;DR

This study investigates the magnetotransport properties of Ta3S2, a candidate type II Weyl semimetal, revealing large anisotropic magnetoresistance, complex Fermi surface behavior, and multiband conduction mechanisms.

Contribution

It provides the first detailed experimental analysis of magnetoresistance and Hall effects in Ta3S2, confirming its Weyl semimetal characteristics and multiband electronic structure.

Findings

Large magnetoresistance up to 8000% at 2 K and 16 T

Observation of anisotropic and field-dependent MR behavior

Identification of multiple Fermi surface pockets via SdH oscillations

Abstract

We have investigated the magnetoresistance (MR) and Hall resistivity properties of the single crystals of tantalum sulfide, Ta3S2, which was recently predicted to be a new type II Weyl semimetal. Large MR (up to ~8000% at 2 K and 16 T), field-induced metal-insulator-like transition and nonlinear Hall resistivity are observed at low temperatures. The large MR shows a strong dependence on the field orientation, leading to a giant anisotropic magnetoresistance (AMR) effect. For the field applied along the b-axis (B//b), MR exhibits quadratic field dependence at low fields and tends towards saturation at high fields; while for B//a, MR presents quadratic field dependence at low fields and becomes linear at high fields without any trend towards saturation. The analysis of the Hall resistivity data indicates the coexistence of a large number of electrons with low mobility and a small number of holes with high mobility. Shubnikov-de Haas (SdH) oscillation analysis reveals three fundamental frequencies originated from the three-dimensional (3D) Fermi surface (FS) pockets. We find that the semi-classical multiband model is sufficient to account for the experimentally observed MR in Ta3S2.