Magnetization-dynamics-induced current in Weyl semimetals

Weyl semimetals recently gather attention because of its novel transport properties, the anomalous Hall effect (AHE) and the chiral magnetic effect (CME), originated from the chiral anomaly. In contrast to the AHE which has been understood after intensive theoretical and experimental studies in condensed matters, the existence of the CME in static cases is still in debate. We propose a magnetically induced current with temporal varying chiral vector potential, which is new transport phenomenon and essentially different from the CME. We consider the magnetically doped Weyl semimetals, and theoretically study the dynamical effect of the magnetization. As a model, we use the Dirac Hamiltonian coupled to the magnetizations with the exchange interaction. We apply field theoretical methods to derive the expression of the current, and find the magnetic-field-driven current induced by the dynamics of magnetic collective excitations. Furthermore, we also conduct the numerical calculation for the lattice model, and obtain the results which agree with the analytical result. Our result, therefore, is not an artifact of taking continuous model, but experimentally observable in solids.