Photomagnetic effect caused by the spin-orbit interaction in a 2D system

The 2D Rashba plane subjected to in-plane magnetic field and normal external alternating electric field is considered. The presence of magnetic field breaks in-plane symmetry of the system. It is shown that the variation of the Rashba spin-orbit constant by alternating field causes transitions between subbands with different helicities. The difference of velocities in subbands results in the stationary in-plane current perpendicular to the magnetic field. The stationary current is studied for scattering by short- and long-range impurities. If the field contains two frequencies Ω±Δ/2, the current response on difference frequency Δ appears. This current is found in the collisionless limit at Δ≪Ω.