Freezing of the dynamics of spontaneous electric field domains in microwave-induced states with a low dissipation

The temperature dependence of the microwave photovoltage has been studied in microwave-induced states of a two-dimensional electron system, which are characterized by an almost dissipationless flow of a low-frequency current. At decreasing temperature, a smooth transition has been found from a bistable state, where the photovoltage demonstrates switching between two levels, which are due to reversals of the spontaneous electric field in a domain structure, to a steady state. The transition occurs as the shift of one of the levels of the bistable photovoltage to the other level accompanied by a decrease in the switching frequency. The results indicate the freezing of the dynamic domain structure in the state corresponding to the more stable configuration of the electric field.