Influence of a parallel magnetic field on the microwave photoconductivity in a high-mobility two-dimensional electron system

摘要

Using a two-axis magnet, we have studied experimentally the influence of a parallel magnetic field (B_∥) on microwave-induced resistance oscillations (MIROs) and zero-resistance states (ZRS) previously discovered in a high-mobility two-dimensional electron system. We have observed a strong suppression of MIRO/ZRS by a modest B_∥ ～ 1 T. In Hall bar samples, magnetoplasmon resonance (MPR) has also been observed concurrently with the MIRO/ZRS. In contrast to the suppression of MIRO/ZRS, the MPR peak is apparently enhanced by B_∥. These findings cannot be explained by a simple modification of single-particle energy spectrum and/or scattering parameters by B_∥.