Magnetization in lateral superlattices induced by strong dc and ac electric fields

We consider nonlinear electric field effects in lateral superlattices with Rashba spin-orbit coupling. Both strong dc and ac electric fields are applied to the superlattice. The pseudomagnetic field associated with the spin-orbit interaction gives rise to a homogeneous spin polarization under nonequilibrium conditions of a biased superlattice. The application of a strong radiation field in the terahertz domain leads to photon resonances, dynamical localization, and delocalization as well as to a reorientation of the field-induced magnetization. We stress the analogy between the field-induced spinless carrier transport and the spin polarization under intense irradiation.