Planar Hall effect in type II Dirac semimetal VAl$_{3}$

TL;DR

This paper reports the observation of a large planar Hall effect in the type II Dirac semimetal VAl₃, confirming its non-trivial topological properties and relativistic chiral anomaly through magnetotransport measurements.

Contribution

It provides experimental evidence of the planar Hall effect in VAl₃, supporting its classification as a type II Dirac semimetal with topological characteristics.

Findings

Large, non-saturating magnetoresistance observed

Presence of two types of high-mobility charge carriers

Robust planar Hall effect up to high temperature

Abstract

The study of electronic properties in topological systems is one of the most fascinating topics in condensed matter physics, which has generated enormous interests in recent times. New materials are frequently being proposed and investigated to identify their non-trivial band structure. While sophisticated techniques such as angle-resolved photoemission spectroscopy have become popular to map the energy-momentum relation, the transport experiments lack any direct confirmation of Dirac and Weyl fermions in a system. From band structure calculations, VAl$_{3}$ has been proposed to be a type II topological Dirac semimetal. This material represents a large family of isostructural compounds, all having similar electronic band structure and is an ideal system to explore the rich physics of Lorentz symmetry violating Dirac fermions. In this work, we present a detailed analysis on the magnetotransport properties of VAl$_{3}$. A large, non-saturating magnetoresistance has been observed. Hall resistivity reveals the presence of two types of charge carriers with high mobility. Our measurements show a large planar Hall effect in this material, which is robust and can be easily detectable up to high temperature. This phenomenon originates from the relativistic chiral anomaly and non-trivial Berry curvature, which validates the theoretical prediction of the Dirac semimetal phase in VAl$_{3}$.