Magnetic Chern Insulators in a monolayer of Transition Metal Trichalcogenides

TL;DR

This paper proposes that monolayer transition metal trichalcogenides can host magnetic Chern insulators due to the interplay of spin-orbit coupling and electron correlation, expanding the understanding of 2D magnetic topological phases.

Contribution

It introduces the possibility of realizing magnetic Chern insulators in quarter-filled honeycomb lattices of transition metal trichalcogenides, supported by phase diagram analysis.

Findings

Ferromagnetic Chern insulating phases exist between metals and normal insulators.

Spin-orbit coupling and electron correlation are key to opening topological gaps.

Rashba spin-orbit and nearest neighbor interactions influence phase stability.

Abstract

A monolayer of transition metal trichalcogenides has received a lot of attention as potential two dimensional magnetic materials. The system has a honeycomb structure of transition metal ions, where both spin-orbit coupling and electron correlation effect play an important role. Here, motivated by these transition metal series with effective doping or mixed valence case, we propose the possible realization of magnetic Chern insulators at quarter filled honeycomb lattice. We show that the interplay of intrinsic spin-orbit coupling and electron correlation opens a wide region of ferromagnetic Chern insulating phases in between metals and normal insulators. Within the mean field approximation, we present the phase diagram of a quarter filled Kane-Mele Hubbard model and also discuss the effects of Rashba spin-orbit coupling and nearest neighbor interactions on it.