What Makes Effective Gating Possible in Two-Dimensional Heterostructures?

TL;DR

This paper explores how quantum properties of electrostatic gating in two-dimensional heterostructures enable tunable magnetic effects, with potential applications in spintronics, using first-principles calculations and physical modeling.

Contribution

It demonstrates that van der Waals bonding is essential for significant electronic structure changes via gating in layered heterostructures, revealing new avenues for device design.

Findings

Gating can control the magnitude and sign of spin polarization in graphene.

van der Waals bonding is crucial for large electronic structure modifications.

Magnetic proximity effects in heterostructures are tunable through gating.

Abstract

Electrostatic gating provides a way to obtain key functionalities in modern electronic devices and to qualitatively alter materials properties. While electrostatic description of such gating gives guidance for related doping effects, inherent quantum properties of gating provide opportunities for intriguing modification of materials and unexplored devices. Using first-principles calculations for Co/bilayer graphene, Co/BN, and Co/benzene, as well as a simple physical model, we show that magnetic heterostructures with two-dimensional layered materials can manifest tunable magnetic proximity effects. van der Waals bonding is identified as a requirement for large electronic structure changes by gating. In particular, the magnitude and sign of spin polarization in physisorbed graphene can be controlled by gating, which is important for spintronic devices.