Effect of rotation of the polarization of linearly polarized microwaves   on the radiation-induced magnetoresistance oscillations
  Light-matter coupling is investigated by rotating, by an angle \theta, the polarization of linearly polarized microwaves with respect to the long-axis of GaAs/AlGaAs Hall-bar electron devices. At low microwave power, P, experiments show a strong sinusoidal variation in the diagonal resistance R_{xx} vs. \theta at the oscillatory extrema, indicating a linear polarization sensitivity in the microwave radiation-induced magnetoresistance oscillations. Surprisingly, the phase shift \theta_{0} for maximal oscillatory R_{xx} response under photoexcitation appears dependent upon the radiation-frequency f, the extremum in question, and the magnetic field orientation or sgn(B). 
A. N. Ramanayaka, R. G. Mani, J. I\~narrea, and W. Wegscheider
cond-mat.mes-hall cond-mat.mtrl-sci