Observation of linear-polarization-sensitivity in the microwave-radiation-induced magnetoresistance oscillations

In the quasi two-dimensional GaAs/AlGaAs system, we investigate the effect of rotating in situ the electric field of linearly polarized microwaves relative to the current, on the microwave-radiation-induced magnetoresistance oscillations. We find that the frequency and the phase of the photoexcited magnetoresistance oscillations are insensitive to the polarization. On the other hand, the amplitudes of the magneto resistance oscillations are remarkably responsive to the relative orientation between the microwave antenna and the current-axis in the specimen. The results suggest a striking linear-polarization-sensitivity in the radiation-induced magnetoresistance oscillations.