Anomalous Hall effect at the Lifshitz transition in ZrTe5

TL;DR

This study combines experimental and theoretical approaches to understand the anomalous Hall effect in ZrTe5, revealing its dependence on Fermi surface topology changes and topological phase transitions near the Lifshitz point.

Contribution

The paper introduces a low energy model that explains the complex Hall response and large anomalous Hall effect in ZrTe5 across various temperatures and magnetic fields, linking it to topological phase transitions.

Findings

Anomalous Hall effect peaks near the Lifshitz transition.

Topological phase transition coexists with the Lifshitz transition.

Model unifies understanding of Hall effects in topological semimetals.

Abstract

Zirconium pentatelluride ZrTe5 is a topological semimetal. The presence of a temperature induced Lifshitz transition, in which the Fermi level goes from the conduction band to the valence band with increasing temperature, provides unique opportunities to study the interplay between Fermi-surface topology, dynamics of Dirac fermions, and Berry curvature in one system. Here we present a combined experimental and theoretical study and show that a low energy model can be used to understand the complicated Hall response and large anomalous Hall effect observed in ZrTe5 over a wide range of temperature and magnetic field. We found that the anomalous Hall contribution dominates the Hall response in a narrow temperature window around the Lifshitz transition, away from which the orbital contribution dominates. Moreover, our results indicate that a topological phase transition coexists with the Lifshitz transition. Our model provides a unifying framework to understand the Hall effect in semimetals with large Zeeman splitting and non-trivial topology.