Ultrafast polarization and magnetization response of multiferroic GaFeO3 using time-resolved nonlinear optical techniques

We have investigated the ultrafast electric and magnetic response of multiferroic GaFeO3 induced by irradiation of a femtosecond laser pulse. By using the polarization selection rules of crystallographic and magnetic second-harmonic generation, the dynamics of electric polarization P and toroidal moment T were simultaneously and separately detected on a femtosecond time scale. The magnetization dynamics was derived by comparing the dynamics of P and T. We demonstrate the availability of time-resolved nonlinear optical techniques for the dynamical probe of multiple degrees of freedom in multiferroics.