Current response to axial gauge fields in noncentrosymmetric magnetic Weyl semimetals

We investigate the electric current response to axial gauge fields in noncentrosymmetric magnetic Weyl semimetals. The absence of both time-reversal and inversion symmetries allows for new types of responses. We systematically calculate the transverse, longitudinal, and Hall responses to axial gauge potentials with both linear and quadratic dispersion relations. The transverse and Hall responses are of comparable magnitude, while the longitudinal response is much smaller. Notably, with increasing frequency, the transverse and Hall response functions manifest a peak whose height is determined by the properties of Weyl fermions and is independent of the axial gauge potential. The main features of the response functions survive in the presence of disorders. As applications of our results, we propose a Hall type magnetopiezoelectric effect, where a transverse sound wave can induce an electric current whose direction is perpendicular to the directions of sound propagation and polarization. Our results also provide a mechanism to excite magnons using electric fields and could be useful for magnon spintronics.