Radiation coupling with two-dimensional electron systems in the low limit of the microwave band: magnetoresistance response

We report on a theoretical study of radiation-induced resistance oscillations and zero-resistance states in two-dimensional electron systems when the irradiation frequency is very low. In this situation the photon energy is much smaller than the spacing between the Landau levels and therefore interlevel transitions are excluded. Experiments show that when these frequencies are used, resistance oscillations disappear and, instead, a strong suppression of magnetoresistance response is obtained. We apply the radiation-driven electron orbit model concluding that the resistance suppression is a manifestation of an oscillation of very large wavelength. Under this regime we study the connection with larger frequencies and the dependence on radiation power and temperature. For high enough radiation intensity, we predict that a regime of zero-resistance states can be reached at these low frequencies, too. The calculated results are in good agreement with experiments.

Radiation coupling with two-dimensional electron systems in the low limit of the microwave band: magnetoresistance response Articles