Chiral Magnetic Effect due to Inhomogeneous Magnetic Fields in Noncentrosymmetric Weyl Semimetals

TL;DR

This paper proposes that inhomogeneous magnetic fields can induce an equilibrium chiral magnetic effect in Weyl semimetals, supported by theoretical calculations and a suggested experimental detection method.

Contribution

It introduces a novel mechanism for equilibrium chiral magnetic effect using inhomogeneous magnetic fields in Weyl semimetals, aligning with the no-go theorem.

Findings

Finite current density generated by inhomogeneous magnetic fields

Spatial integration of current equals zero, consistent with no-go theorem

Proposed experimental setup for detection

Abstract

The chiral magnetic effect is a phenomenon where an electromagnetic current is generated along a magnetic field. Recently, in nonequilibrium systems, negative longitudinal magnetoresistance has been observed experimentally in Dirac/Weyl semimetals, which provides evidence for the chiral magnetic effect as a nonequilibrium current. On the other hand, the emergence of the chiral magnetic effect as an equilibrium current is still controversial. We propose a possible realization of the chiral magnetic effect as an equilibrium current using inhomogeneous magnetic fields. By employing tight-binding calculations and linear response theory, we demonstrate that a finite current density is generated by inhomogeneous magnetic fields, while the spatial integration of the current is equal to zero, which is consistent with the so-called "no-go theorem" of the chiral magnetic effect in real lattice systems. Moreover, we propose an experimental setup to detect the effect in Weyl semimetal materials.