New emerging effects in microwave-induced resistivity oscillations in 2D electron systems: Bichromatic radiation, anharmonicity and polarization immunity

We analyze theoretically new experimental outcomes on microwave-induced resistivity oscillations in two-dimensional electron systems. These new experiments correspond to bichromatic microwave radiation, resistivity anharmonicity and polarization immunity. We provide an explanation to each of the three experimental evidences using a theoretical model developed by the authors as a common basis. According to this model the origin of microwave-induced resistivity oscillations and zero resistance states can be explained by the dynamics of the Larmor orbit centers which oscillate classically back and forth with the same frequency as the microwave field. Good agreement between experiment and theory is achieved for the three cases.