Photomagnetization of a Landau-Lifshitz domain structure by circularly polarized light and the velocity of domain wall movement induced by light

It is shown that photomagnetization can evoked as a result of absorption of circularly polarized light by multidomian magnets possessing circular dichroism. The cause of the effect is that the magnitude of the exchange interaction parameter in different domains can be different. In magnetic semiconductors interaction parameter in different domians can be different. In magnetic semiconductors this is due to the different concentration of the photocarriers in various domains. The equilibrium values of the per+od and domain widths and also the relative magnitude of photomagnetization are found for the Landau-Lifshitz structure. The velocity of an interdomian wall moving under the action of light i.s considered. Estimations carried out for CdCr2Se4 show that at light intensities of the order of 10 W/cm2 the photomagnetization may reach a value of the order of 10-2 for ΔM/M0