Anomalous resistance overshoot in the integer quantum Hall effect

TL;DR

This paper investigates the anomalous overshoot in Hall resistance during the integer quantum Hall effect, revealing its dependence on temperature, device definition, and gate voltages, explained by scattering between incompressible channels.

Contribution

It provides new experimental insights into the overshoot effect, showing its enhancement at higher temperatures and controllability via gate voltages, with a comprehensive scattering-based explanation.

Findings

Overshoot effect is more pronounced at higher temperatures in shallow etched Hall bars.

The amplitude of the overshoot can be controlled by gate voltages.

The effect occurs at both odd and even integer plateaus, suggesting a spin-independent mechanism.

Abstract

In this work we report experiments on defined by shallow etching narrow Hall bars. The magneto-transport properties of intermediate mobility two-dimensional electron systems are investigated and analyzed within the screening theory of the integer quantized Hall effect. We observe a non-monotonic increase of Hall resistance at the low magnetic field ends of the quantized plateaus, known as the overshoot effect. Unexpectedly, for Hall bars that are defined by shallow chemical etching the overshoot effect becomes more pronounced at elevated temperatures. We observe the overshoot effect at odd and even integer plateaus, which favor a spin independent explanation, in contrast to discussion in the literature. In a second set of the experiments, we investigate the overshoot effect in gate defined Hall bar and explicitly show that the amplitude of the overshoot effect can be directly controlled by gate voltages. We offer a comprehensive explanation based on scattering between evanescent incompressible channels.