Surface Acoustic-Wave-Induced Magnetoresistance Oscillations in a Two-Dimensional Electron Gas

We study the geometrical commensurability oscillations imposed on the resistivity of 2D electrons in a perpendicular magnetic field by a propagating surface acoustic wave (SAW). We show that, for $\omega <{\omega }_c$, this effect contains an anisotropic dynamical classical contribution increasing the resistivity and a nonequilibrium quantum contribution isotropically decreasing the resistivity, and we predict zero-resistance states associated with geometrical commensurability at large SAW amplitude.

Figure 1

Magnetoresistance geometrical oscillations for static ($\omega \tau =0$) and dynamic ($\omega \tau =20$) modulations of a 2DEG, for $ql=600$, and $\mathcal{E}=0.01$.