Quantum phase transition between a topological and a trivial semimetal from holography

TL;DR

This paper models a quantum phase transition between topological and trivial semimetals using holography, highlighting the role of time-reversal symmetry breaking and mass deformation, with observable effects like the anomalous Hall effect.

Contribution

It introduces a holographic framework to study topological phase transitions in Weyl semimetals, connecting RG flow to topological properties.

Findings

Transition from topological to trivial phase controlled by mass and time-reversal breaking ratio

Presence of anomalous Hall effect in the topologically nontrivial phase

RG flow leads to time-reversal symmetry restoration in the trivial phase

Abstract

We present a holographic model of a topological Weyl semimetal. A key ingredient is a time-reversal breaking parameter and a mass deformation. Upon varying the ratio of mass to time-reversal breaking parameter the model undergoes a quantum phase transition from a topologically nontrivial semimetal to a trivial one. The topological nontrivial semimetal is characterised by the presence of an anomalous Hall effect. The results can be interpreted in terms of the holographic renormalization group (RG) flow leading to restoration of time-reversal at the end point of the RG flow in the trivial phase.