Localized charge in various configurations of magnetic domain wall in Weyl semimetal

TL;DR

This paper numerically studies how magnetic domain walls in Weyl semimetals localize electric charge depending on their texture, enabling electric-field-driven domain wall motion without current, which could reduce Joule heating.

Contribution

It introduces a numerical method to analyze localized charge in magnetic domain walls of Weyl semimetals and reveals a new mechanism for domain wall motion driven by electric fields.

Findings

Localized charge depends on domain wall texture.

Charge localization arises from Landau state degeneracy.

Electric fields can move domain walls without current.

Abstract

We numerically investigate the electronic properties of magnetic domain walls formed in a Weyl semimetal. Electric charge distribution is computed from the electron wave functions, by numerically diagonalizing the Hamiltonian under several types of domain walls. We find a certain amount of electric charge localized around the domain wall, depending on the texture of the domain wall. This localized charge stems from the degeneracy of Landau states under the axial magnetic field, which corresponds to the curl in the magnetic texture. The localized charge enables one to drive the domain wall motion by applying an external electric field without injecting an electric current, which is distinct from the ordinary spin-transfer torque and is free from Joule heating.