Hysteresis and Spikes in the Quantum Hall Effect

TL;DR

This paper reports the observation of sharp peaks and hysteresis in the quantum Hall effect of a 2DEG, revealing a parallel conduction channel's role in these phenomena and how bias voltage influences them.

Contribution

It identifies a parallel conduction channel as the cause of hysteresis and spikes in the quantum Hall effect, and shows how bias voltage can suppress these features.

Findings

Sharp peaks and hysteresis observed in 2DEG transport

Grounding contacts alters peak strength

Negative bias voltage suppresses the features

Abstract

We observe sharp peaks and strong hysteresis in the electronic transport of a two-dimensional electron gas (2DEG) in the region of the integral quantum Hall effect. The peaks decay on time scales ranging from several minutes to more than an hour. Momentary grounding of some of the contacts can vastly modify the strength of the peaks. All these features disappear under application of a negative bias voltage to the backside of the specimen. We conclude, that a conduction channel parallel to the high mobility 2DEG is the origin for the peaks and their hysteretic behavior.