Chiral anomaly in Dirac semimetals due to dislocations

TL;DR

This paper demonstrates that dislocations in Dirac semimetals host chiral fermion modes due to emergent magnetic flux, leading to observable chiral anomaly effects such as axial charge pumping under electric fields.

Contribution

It reveals that dislocations induce chiral modes in Dirac semimetals, providing a new mechanism for chiral anomaly phenomena in these materials.

Findings

Dislocations carry emergent magnetic flux enabling chiral modes.

A single massless fermion mode propagates along the dislocation.

External electric fields induce axial charge flow near dislocations.

Abstract

The dislocation in Dirac semimetal carries an emergent magnetic flux parallel to the dislocation axis. We show that due to the emergent magnetic field the dislocation accommodates a single fermion massless mode of the corresponding low-energy one-particle Hamiltonian. The mode is propagating along the dislocation with its spin directed parallel to the dislocation axis. In agreement with the chiral anomaly observed in Dirac semimetals, an external electric field results in the spectral flow of the one-particle Hamiltonian, in pumping of the fermionic quasiparticles out from the vacuum, and in creating a nonzero axial (chiral) charge in the vicinity of the dislocation.