Bulk photovoltaic effect induced by elliptically-polarized light

Shift current has been considered as one of the major orgins for bulk photovoltaic effets. In this study, using time-dependent perturbation theory, we investigate the light polarization effect on shift current. We give a general formula for shift current indcued by elliptically-polarized (EP) light, which represents the most general form of a polarized light. By using a two-band model widely applied in 2D materials, we calculate the EP shift current quantitatively, and compare it with the linearly-polarized shift current and circularly-polarized injection current.