Chiral magnetic effect in two-band lattice model of Weyl semimetal

TL;DR

This paper demonstrates the existence of the chiral magnetic effect in a two-band Weyl semimetal model using linear-response theory, highlighting the importance of limiting procedures and the role of Berry curvature over chirality.

Contribution

It establishes the CME within a lattice model, clarifies the impact of limiting procedures, and shows the CME coefficient's dependence on model parameters beyond linearized approximations.

Findings

CME exists in the two-band Weyl semimetal model.

The limiting procedure critically affects transport property calculations.

CME coefficient depends on model parameters and persists beyond linearized models.

Abstract

Employing a two-band model of Weyl semimetal, the existence of the chiral magnetic effect (CME) is established within the linear-response theory. The crucial role played by the limiting procedure in deriving correct transport properties is clarified. Besides, in contrast to the prediction based on linearized effective models, the value of the CME coefficient in the uniform limit shows nontrivial dependence on various model parameters. Even when these parameters are away from the region of the linearized models, such that the concept of chirality may not be appropriate, this effect still exists. This implies that the Berry curvature, rather than the chiral anomaly, provides a better understanding of this effect.