Interaction robustness of the chiral anomaly in Weyl semimetals and Luttinger liquids from a mixed anomaly approach

Abstract

The chiral anomaly is one of the robust quantum effects in relativistic field theories with a chiral symmetry where charges in chiral sectors appear to be separately conserved. The chiral anomaly, which is often associated with a renormalization-invariant topological term, is a violation of this conservation law due to quantum effects. Such anomalies manifest in Weyl materials as an electromagnetic field-induced transfer of charge between Fermi pockets. However, the emergent nature of the conservation of chiral charge leads to manifestations of the chiral anomaly response that depend on the details of the system such as the strength of interactions. In this paper, we apply an approach where the chiral symmetry in solid materials is replaced by the combination of charge $U(1)$ gauge and spatial translation symmetry. The chiral anomaly in this case is replaced by a mixed anomaly between the two symmetries and the chiral charge can be defined as being proportional to the total momentum. We show that the chiral anomaly associated with this chiral charge is unrenormalized by interactions in contrast to other chiral charges in $(1+1)D$ whose renormalization is regularization dependent. In $(3+1)$D Weyl systems, this chiral anomaly is equivalent to the charge transferred between Fermi surfaces which can be measured through changes in Fermi-surface-enclosed volume. We propose a pump-probe technique to measure this.