The holographic Weyl semi-metal

TL;DR

This paper introduces a holographic model of a Weyl semi-metal that exhibits a quantum phase transition characterized by the anomalous Hall effect, providing insights into strongly coupled topological phases without quasiparticle excitations.

Contribution

It develops a holographic framework for Weyl semi-metals and analyzes their topological phase transition through a holographic RG flow, contrasting with weakly coupled models.

Findings

Quantum phase transition driven by a mass parameter change

Topologically non-trivial to trivial transition identified by AHE

Absence of quasiparticles in the holographic model affects topological interpretation

Abstract

We present a holographic model of a Weyl semi-metal. We show that upon varying a mass parameter the model undergoes a quantum phase transition from a topologically non-trivial state to a trivial one. The order parameter for this phase transition is the anomalous Hall effect (AHE). We give an interpretation of the results in terms of a holographic RG flow and compare to a weakly coupled field theoretical model. Since there are no quasiparticle excitations in the strongly coupled holographic model the topological phase can not be bound to notions of topology in momentum space.