Magnetic field-induced resistivity upturn and exceptional magneto-resistance in Weyl semimetal TaSb2

TL;DR

This study investigates the magneto-transport properties of TaSb2, revealing large magneto-resistance, resistivity plateau, and evidence of chiral anomaly, establishing it as a Type-II Weyl semimetal with high electron mobility.

Contribution

It provides experimental evidence of anomalous chiral transport and detailed analysis of magneto-resistance in TaSb2, a newly identified topological semimetal.

Findings

TaSb2 exhibits extremely high, non-saturating magneto-resistance.

Resistivity plateau at low temperatures is explained by classical Kohler scaling.

Negative longitudinal magneto-resistance indicates chiral anomaly.

Abstract

We study magneto-transport properties in single crystals of TaSb_2, which is a recently discovered topological semimetal. In the presence of magnetic field, the electrical resistivity shows onset of insulating behaviour followed by plateau at low temperature. Such resistivity plateau is generally assigned to topological surface states. TaSb2 exhibits extremely high magneto-resistance with non-saturating field dependence. We find that aspects of extremely large magneto resistance and resistivity plateau are well accounted by classical Kohler scaling. Unambiguous evidence for anomalous Chiral transport is provided with observation of negative longitudinal magneto-resistance. Shubnikov-de Haas oscillations reveal two dominating frequencies, 201 T and 455 T. These aspects categorize TaSb2 as a Type-II Weyl semimetal. At low temperature, the field dependence of Hall resistivity shows non-linear behaviour that indicates the presence of two types of charge carriers in consonance with reported electronic band structure. Analysis of Hall resistivity imply very high electron mobilities.