Hysteretic behavior and evidence for domain formation in a double-layer quantum Hall system at total filling factor 2

TL;DR

This paper investigates anomalous hysteretic behavior in a double-layer 2D hole gas at even integer quantum Hall states, linking it to magnetic domain formation and showing that adding a metal film suppresses these effects.

Contribution

It provides experimental evidence for magnetic domain formation in a double-layer quantum Hall system at even filling factors, supporting theoretical predictions.

Findings

Hysteresis observed in resistances at even integer filling factors

Weak temperature dependence of resistance minima

Suppression of anomalies with a metal film on top

Abstract

We report anomalous behavior in a double-layer two dimensional hole gas (2DHG) at even integer filling factors which includes hysteresis in the longitudinal and Hall resistances and a very weak temperature dependence of the resistance minima. All anomalies disappear and the conventional quantum Hall effect behavior recovers when a thin metal film is placed on top of the 2DHG. The behavior is attributed to presence of the theoretically predicted magnetic ordering at even integer filling factors which causes the formation of macroscopic spin-charge domains.