Giant semiclassical magnetoresistance in high mobility TaAs2 semimetal

TL;DR

This paper reports the discovery of giant positive magnetoresistance in high mobility TaAs2 semimetal, with quadratic field dependence and origins linked to electron-hole compensation, reaching over 1,200,000% at low temperature and high magnetic field.

Contribution

It demonstrates the colossal positive magnetoresistance in TaAs2, highlighting its semiclassical origin and exceptional magnitude compared to other semimetals.

Findings

Quadratic magnetoresistance fits well over a wide temperature range.

Magnetoresistance exceeds 1,200,000% at 9 T and 2 K.

Giant MR is due to electron-hole compensation in TaAs2.

Abstract

We report the observation of colossal positive magnetoresistance (MR) in single crystalline, high mobility TaAs2 semimetal. The excellent fit of MR by a single quadratic function of the magnetic field B over a wide temperature range (T = 2-300 K) suggests the semiclassical nature of the MR. The measurements of Hall effect and Shubnikov-de Haas oscillations, as well as band structure calculations suggest that the giant MR originates from the nearly perfectly compensated electrons and holes in TaAs2. The quadratic MR can even exceed 1,200,000% at B = 9 T and T = 2 K, which is one of the largest values among those of all known semi-metallic compounds including the very recently discovered WTe2 and NbSb2. The giant positive magnetoresistance in TaAs2, which not only has a fundamentally different origin from the negative colossal MR observed in magnetic systems, but also provides a nice complemental system that will be beneficial for applications in magnetoelectronic devices