Direct-current control of radiation-induced magnetoresistance oscillations in two-dimensional semiconductors

Magneto-photoresistance oscillations in two-dimensional electron systems driven simultaneously by a sub-terahertz irradiation and a strong direct current, are analyzed within a unified microscopic theory treating both excitations on an equal footing. The radiation-induced photoresistance oscillations are described by a parameter epsilon(w) proportional to the radiation frequency, while in the case without radiation the magnetoresistance oscillations are governed by a parameter epsilon(j) proportional to the current density. In the presence of both a radiation and a strong current, the combined parameter epsilon(w) + epsilon(j) is shown to control the main magnetoresistance oscillations, in agreement with the experimental finding.