Momentum relaxation in a holographic Weyl semimetal

TL;DR

This paper investigates how momentum relaxation affects the phase transition and transport properties of a holographic Weyl semimetal, revealing that increased relaxation suppresses the Weyl phase and alters conductivity behaviors.

Contribution

It provides a holographic analysis of momentum relaxation effects on Weyl semimetals, including phase transition shifts and conductivity changes, aligning with weakly coupled theory predictions.

Findings

Critical phase transition value decreases with relaxation strength.

Weyl semimetal phase diminishes and eventually disappears as relaxation increases.

Transport properties like conductivities are significantly affected by momentum relaxation.

Abstract

We study the effects of momentum relaxation on the holographic Weyl semimetal which exhibits a topological quantum phase transition between the Weyl semimetal phase and a topological trivial phase. The conservation of momentum in the field theory is broken by the axion fields in holography. The topological Weyl semimetal phase is characterized by a nontrivial anomalous Hall conductivity. We find that the critical value of the phase transition decreases when we increase the momentum relaxation strength up to a special value, above which it goes to zero. This indicates that the Weyl semimetal phase shrinks and finally disappears as the momentum relaxation strength is increased, which is consistent with the weakly coupled field theory predictions. We also study the behavior of transverse/longitudinal conductivities and low temperature dependence of the d.c.resistivities with respect to momentum relaxation strength.