# Topological responses from chiral anomaly in multi-Weyl semimetals

## TL;DR

This paper investigates the topological responses and transport phenomena in multi-Weyl semimetals caused by the chiral anomaly, revealing how axial fields influence conductivity and chirality accumulation, with implications for valleytronics.

## Contribution

It introduces a systematic study of electromagnetic and axial field effects on transport in multi-Weyl semimetals, highlighting new mechanisms for chirality control.

## Key findings

- Axial vector potential modifies anomalous Hall conductivity linearly.
- Axial electric field induces an axial Hall current proportional to Weyl node separation.
- Chirality accumulation can be engineered without external electromagnetic fields.

## Abstract

Multi-Weyl semimetals are a kind of topological phase of matter with discrete Weyl nodes characterized by multiple monopole charges, in which the chiral anomaly, the anomalous nonconservation of an axial current, occurs in the presence of electric and magnetic fields. Electronic transport properties related to the chiral anomaly in the presence of both electromagnetic fields and axial electromagnetic fields in multi-Weyl semimetals are systematically studied. It has been found that the anomalous Hall conductivity has a modification linear in the axial vector potential from inhomogeneous strains. The axial electric field leads to an axial Hall current that is proportional to the distance of Weyl nodes in momentum space. This axial current may generate chirality accumulation of Weyl fermions through delicately engineering the axial electromagnetic fields even in the absence of external electromagnetic fields. Therefore, this work provides a nonmagnetic mechanism of generation of chirality accumulation in Weyl semimetals and might shed new light on the application of Weyl semimetals in the emerging field of valleytronics.