Floquet states of semiconductor superlattices under an in-plane magnetic field and laser radiation

The motion of an electron in a semiconductor superlattice, undergoing the combined action of a static magnetic field perpendicular to its growth direction and intense electromagnetic radiation is considered. Exact numerical solutions of the time-dependent Schrödinger equation are found for a superlattice with a sinusoidal potential. Quasienergies are calculated as function of the cyclotronic orbit center position for different values of laser intensity. The features of the resulting spectra of magnetic subbands are studied. The results are compared with those previously calculated in the Kramers-Henneberger approximation. Nonlinear effects are important for laser frequencies close to the cyclotronic frequency even for moderate laser intensities. The occurrence of band suppression and dynamic localization is discussed.