From zero resistance states to absolute negative conductivity in microwave irradiated two-dimensional electron systems

Recent experimental results regarding a two-dimensional electron gas subjected to microwave radiation reveal that magnetoresistivity, apart from presenting oscillations and zero resistance states, can evolve to negative values at minima. Here the authors present a theoretical model which explains the transition from zero resistance states to absolute negative conductivity in terms of multiphoton assisted electron scattering due to charged impurities and shows how this transition can be driven by tuning microwave frequency and intensity. This opens the possibility of controlling the magnetoconductivity in microwave driven nanodevices and understanding the novel optical and transport properties of such devices. (c) 2006 American Institute of Physics.