Study of the phase-shift in the linear-polarization-angle-dependence of the microwave radiation-induced magnetoresistance oscillations in the GaAs/AlGaAs system*

Transport studies of microwave- and terahertz-induced magneto-resistance oscillations (MTIMRO) identified novel photo-excited zero-resistance states in the GaAs/AlGaAs two-dimensional electron system system. Some theories based on the premise of linear-polarization-insensitivity have been developed for the MRIMRO. Some studies have shown, however, a strong linear polarization sensitivity of MTIMRO [1,2] using new experimental methods. In addition, Ramanayaka \textit{et al.} [2] has observed that using fitting formula, R$_{\mathrm{xx}}(\theta )=$A $\pm$ Ccos$^{2}(\theta $-$\theta_{0})$, to sinusoidal variation of diagonal resistance, R$_{\mathrm{xx}}$, with polarization angle $\theta $, the extracted phase shift, $\theta_{0}$, depends on radiation frequency, magnetic field $B$, sign of $B$ [2]. Here, in addition to those mentioned factors, we investigate the dependence of the phase shift $\theta_{0}$ in the linear-polarization-angle-dependence upon sample geometry. \\[4pt] [1] R. G. Mani \textit{et al.}, Phys. Rev. B 84, 085308 (2011). \\[0pt] [2] A. N. Ramanayaka \textit{et al.}, Phys. Rev. B 85, 205315 (2012).