Strong magnetic proximity effect in Van der Waals heterostructures driven by direct hybridization

TL;DR

This paper introduces a novel magnetic proximity effect driven by spin-dependent hybridization between a non-magnetic conductor and a ferromagnetic insulator, demonstrated through DFT calculations on graphene and CrI3, and tunable by electric fields.

Contribution

It reveals a new hybridization-based magnetic proximity effect that significantly influences non-magnetic layers and can be controlled electrically, unlike traditional exchange proximity effects.

Findings

Strong hybridization of graphene with CrI3 in one spin channel

Effect robustness against lattice mismatch and twist angle variations

Electric field modulation of hybridization strength

Abstract

We propose a new class of magnetic proximity effects based on the spin dependent hybridization between the electronic states at the Fermi energy in a non-magnetic conductor and the narrow spin split bands of a ferromagnetic insulator. Unlike conventional exchange proximity, we show this hybridization proximity effect has a very strong influence on the non-magnetic layer and can be further modulated by application of an electric field. We use DFT calculations to illustrate this effect in graphene placed next to a monolayer of CrI$_3$, a ferromagnetic insulator. We find strong hybridization of the graphene bands with the narrow conduction band of CrI$_3$ in one spin channel only. We show that our results are robust with respect to lattice mismatch and twist angle variations. Furthermore, we show that an out-of-plane electric field can be used to modulate the hybridization strength, paving the way for applications.