Microwave-induced resistance oscillations on a high-mobility two-dimensional electron gas: Exact waveform, absorption/reflection and temperature damping

In this work we address experimentally a number of unresolved issues related to microwave induced resistance oscillations (MIROs) leading to the zero-resistance states observed recently on 2D electron gases in GaAs AlGaAs heterostructures. We stress the importance of the electrodynamic effects detected in both reflection and absorption experiments, although they are not revealed in transport experiments on very high mobility samples. We also study the exact waveform of MIROs and their damping due to temperature. A simple equation is given, which can be considered as phenomenological, which describes precisely the experimental MIROs waveform. The waveform depends only on a single parameter-the width of the Landau levels, which is related to the quantum lifetime. A very good correlation was found between the temperature dependencies of the quantum lifetime from MIROs and the transport scattering time from the electron mobility with a ratio τtr τq 20. It is found that the prefactor in the equation for MIROs decays as 1 T2 with the temperature which can be explained within the distribution function model suggested by Dmitriev. The results are compared with measurements of the Shubnikov-de Haas oscillations down to 30mK on the same sample.