Magnetic anisotropy energies and metal-insulator transitions in monolayers of $\alpha$-RuCl$_3$ and OsCl$_3$ on graphene

TL;DR

This study uses first-principles calculations to demonstrate how graphene and external electric fields can tune the electronic and magnetic properties, including metal-insulator transitions and magnetic anisotropy, in monolayers of RuCl and OsCl.

Contribution

It reveals the potential to control electronic and magnetic properties of transition metal trichloride monolayers via graphene and electric fields, a novel approach in 2D material engineering.

Findings

Graphene induces inhomogeneous n-type doping in RuCl and OsCl monolayers.

External electric fields can tune the occupancy of Hubbard bands.

Control over metal-insulator transitions and magnetic anisotropy energies is achieved.

Abstract

Transition metal thriclorides, with $4d$ or $5d$ electrons, are materials at the forefront of recent studies about the interplay of spin-orbit coupling and strong Coulomb interactions. Within our first-principles calculations (DFT+$U$+SOC) we study the effects of graphene on the electronic and magnetic properties of the monolayers of $\alpha$-RuCl$_3$ and OsCl$_3$. Despite the spatially inhomogeneous $n$-type doping induced by graphene, we show that the occupancy of the upper Hubbard bands of MLs of \rucl and OsCl$_3$ can be tuned through external electric fields, and allows the control of (i) metal-insulator transitions, and (ii) the magnetic easy-axis and anisotropy energies. Our findings point towards the tunning of electronic and magnetic properties of transition metal thriclorides monolayers by using graphene and external electronic fields.