Conversion between dipoles with different spatial parities by circularly polarized light

Abstract

We investigate the effect of a circularly polarized light on multipoles based on the Floquet formalism. We show that the irradiation of the circularly polarized light converts the spatial parity of dipoles at the microscopic level; the electric (magnetic toroidal) dipole as a time-reversal-even (time-reversal-odd) polar vector is transformed into the electric toroidal (magnetic) dipole as a time-reversal-even (time-reversal-odd) axial vector and vice versa. Furthermore, various monopoles and higher-rank multipoles are additionally induced by the circularly polarized light. Our results indicate that the circularly polarized light is useful in inducing unconventional toroidal multipoles in conventional ferroelectric and ferromagnetic materials.