DC-current induced magneto-oscillations in very high-mobility 2D electron gas

We report on a systematic experimental study of DC-current induced magneto-oscillations [1] using Hall bar samples of very high-mobility (8-20 $\times $ 10$^{6}$ cm$^{2}$/Vs) GaAs/Al$_{x}$Ga$_{1-x}$As heterostructures. Previously we show that remarkable nonlinear resistance and $1/B$ oscillations can arise when a high bias current ($I_{x})$ is passed through a Hall bar (width $w)$, and the effect can be explained by a Zener tunneling model in the presence of a tilting Hall field [1]. Data of resistance $R_{xx} \equiv V_x /I_x $, differential resistance $r_{xx} \equiv \partial V_x /\partial I_x $, and $r_{xx} '\equiv \partial r_{xx} /\partial I_x $ in higher mobility samples, which show higher order oscillations, have confirmed the validity of this model. Our temperature dependent date show that this effect can persist to $k_B T>\hbar \omega _c $, where $\hbar \omega _c $ is the cyclotron energy. [1] Yang et al, Phys. Rev. Lett.\textbf{ 89}, 076801 (2002).