Role of electron-electron interactions in nonlinear transport in two-dimensional electron systems

We study the temperature evolution of the nonlinear oscillatory magnetoresistance in a high-mobility two-dimensional electron system subject to a strong dc electric field. We find that the decay of the oscillation amplitude with increasing temperature originates primarily from the increase in the quantum scattering rate entering the Dingle factor. We attribute this behavior to electron-electron interaction effects.

Figure 1

(Color online) Differential magnetoresistivity $r\left(B\right)$ at $I=80\mu \text{A}$ for temperature from 2.0 to 5.0 K in 0.5 K steps. The traces are vertically offset for clarity by $0.2\Omega$. Vertical lines $\left({ϵ}_{\text{dc}}=1,2,3\right)$ mark oscillation maxima.

Figure 2

(Color online) Circles show normalized oscillation amplitude $\Delta r/{\rho }_0$ vs $1/B$ for $T=2$, 3, 4, and 5 K. Lines represent fits to $\text{exp}\left(-2\pi /{\omega }_c{\tau }_q\right)$.

Figure 3

(Color online) Quantum scattering rate $1/{\tau }_q$ vs $T^2$ (open circles) and linear fit (solid line).

Figure 4

(Color online) Circles show normalized oscillation amplitude $\Delta r/{\rho }_0$ vs $2\pi /{\omega }_c{\tau }_q$ for all temperatures studied. Line marks a slope of $\text{exp}\left(-2\pi /{\omega }_c{\tau }_q\right)$.