Insulating charge transfer ferromagnetism

TL;DR

This paper introduces a mechanism for insulating ferromagnetism in honeycomb Hubbard models of semiconductor moiré superlattices, enabling quantum anomalous Hall states without Hund's coupling, applicable to general charge transfer systems.

Contribution

It presents a novel charge transfer mechanism for insulating ferromagnetism that does not rely on Hund's coupling, expanding understanding of magnetic states in moiré materials.

Findings

Ferromagnetism emerges at critical charge transfer regimes.

Stabilization of quantum anomalous Hall states without Hund's coupling.

Applicability to general charge transfer systems when particle-hole symmetry is broken.

Abstract

We propose a mechanism for insulating ferromagnetism in the honeycomb Hubbard model of semiconductor moir\'e superlattices. The ferromagnetism emerges at critical charge transfer regime, stabilizing the quantum anomalous Hall state without Hund's coupling. We further note the ferromagnetic exchange applies to general charge transfer systems when breaking particle-hole symmetry.