Photo-Induced Anomalous Hall Effect in 2D Transition-Metal Dichalcogenide

Illumination of a circularly polarized a.c. pump field induces a valley polarization in two-dimensional transition metal dichalcogenides (TMDs), which results in an anomalous Hall voltage in response to a d.c. bias. In this work, we develop a theory for this photovoltaic valley-resolved anomalous Hall effect in undoped TMDs. A quantum kinetic equation is used to study the non-equilibrium carrier populations and time-averaged transport currents under the simultaneous influence of the strong a.c pump field and the weak d.c probe field. Our results for the photo-induced longitudinal and Hall conductivities show strong resonant features when the pump field frequency reaches the spin-split band-to-band transition energies.