Nernst Thermopower of Time-Reversal Breaking Type-II Weyl Semimetals

TL;DR

This paper provides a theoretical analysis of thermoelectric transport, specifically the Nernst effect, in time-reversal breaking type-II Weyl semimetals, highlighting the roles of anomalous contributions, scattering times, and temperature-dependent chemical potential.

Contribution

It offers a novel theoretical framework for understanding thermoelectric transport in type-II Weyl semimetals, including the interplay of anomalous and non-anomalous effects under magnetic fields.

Findings

Increasing scattering times enhances thermoelectric transport.

Temperature-dependent chemical potential significantly affects the Nernst thermopower.

Balance between anomalous and non-anomalous contributions varies with external magnetic field.

Abstract

Weyl semimetals host linear energy dispersions around Weyl nodes, as well as monopoles of Berry curvature in momentum space around these points. These features give rise to unique transport signatures in a Weyl semimetal, such as transverse transport without an applied magnetic field, known as anomalous transport. The type-II Weyl semimetal, recently experimentally demonstrated in several materials, is classified by a tilting of the Weyl nodes. This paper provides a theoretical study on thermoelectric transport in time-reversal breaking type-II Weyl semimetals. Our results examine the balance between anomalous and non-anomalous contributions to the Nernst effect when subject to an external magnetic field. We also show how increasing scattering times have on enhancing effect on thermoelectric transport in these materials. Since a temperature-dependent chemical potential has been theoretically shown to be paramount when considering anomalous transport, we also study how similar considerations impact the Nernst thermopower in the non-anomalous case.