Electrical Control of Exchange Bias Mediated by Graphene

TL;DR

This paper theoretically demonstrates how graphene can mediate and electrically control exchange bias between ferromagnetic layers, with potential for room-temperature spintronic applications.

Contribution

It introduces a theoretical model showing electrical control of exchange bias mediated by graphene, highlighting the influence of layer properties on magnetic interactions.

Findings

Exchange bias depends strongly on graphene properties.

Electrical control of magnetic interactions is feasible at room temperature.

Differences between mono- and bilayer graphene affect the exchange bias characteristics.

Abstract

The role of graphene in mediating the exchange interaction is theoretically investigated when it is placed between two ferromagnetic dielectric materials. The calculation based on a tight-binding model illustrates that the magnetic interactions at the interfaces affect not only the graphene band structure but also the thermodynamic potential of the system. This induces an indirect exchange interaction between the magnetic layers that can be considered in term of an effective exchange bias field. The analysis clearly indicates a strong dependence of the effective exchange bias on the properties of the mediating layer, revealing an effective mechanism of electrical control even at room temperature. This dependence also results in qualitatively different characteristics for the cases involving mono- and bilayer graphene.