Quantum Anomalies in Strained Weyl Semimetals

The chiral anomaly gives the topological response of Weyl semimetals to an external perturbation, insensitive to local details of the Hamiltonian. The recent identification of strain as axial fields in these materials gives rise to other anomalies, known from high-energy theory. However, these anomalies driven by axial fields are not necessary gauge-invariant or charge-conserving; in fact, two different formulations exist, realizing just one of these conditions. In this work, we propose a way to resolve this ambiguity, supported by a lattice model that provides an intuitive picture. We identify experimental signatures and argue about their stability in presence of disorder.