Radiation-induced zero-resistance states in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="normal">Ga</mml:mi><mml:mi mathvariant="normal">As</mml:mi><mml:mo>∕</mml:mo><mml:mi mathvariant="normal">Al</mml:mi><mml:mi mathvariant="normal">Ga</mml:mi><mml:mi mathvariant="normal">As</mml:mi></mml:mrow></mml:math>heterostructures: Voltage-current characteristics and intensity dependence at the resistance minima

High mobility two-dimensional electron systems exhibit vanishing resistance over broad magnetic field intervals upon excitation with microwaves, with a characteristic reduction of the resistance with increasing radiation intensity at the resistance minima. Here, we report experimental results examining the voltage-current characteristics, and the resistance at the minima versus the microwave power. The findings indicate that a non-linear $V\text{\ensuremath{-}}I$ curve in the absence of microwave excitation becomes linearized under irradiation, unlike expectations, and they suggest a similarity between the roles of the radiation intensity and the inverse temperature.