Interlayer Magnetic Coupling and the Quantum Hall Effect in Multilayer Electron Systems

TL;DR

This paper investigates how electron-electron interactions influence multilayer electron systems at filling factor unity, revealing various magnetic phases with quantum Hall effects driven by different energy gaps.

Contribution

It introduces a comprehensive analysis of interlayer magnetic phases and their connection to quantum Hall states in multilayer systems considering electron interactions.

Findings

Identification of ferromagnetic, canted antiferromagnetic, and paramagnetic phases.

Each phase exhibits a finite activation energy indicating quantum Hall effect.

Different mechanisms (exchange energy and interwell coherence) cause the energy gaps.

Abstract

We study the effect that the electron-electron interaction has on the properties of a multilayer electron system. We consider the case corresponding to filling factor unity in each layer. We find that as a function of the sample parameters the system has ferromagnetic, canted antiferromagnetic or paramagnetic interlayer spin correlations. These three ground states are QHE phases, because of the existence of a finite activation energy. In the ferromagnetic phase the gap is due to the intrawell exchange energy, whereas in the paramagnetic phase the gap appears due to the spatial modulation of the interwell coherence.