Effective gating and tunable magnetic proximity effects in two-dimensional heterostructures

Authors

Predrag Lazic, University at Buffalo, State University of New York
Kirill Belashchenko, University of Nebraska-LincolnFollow
Igor Zutic, University at Buffalo, State University of New York

Date of this Version

2016

Document Type

Article

Citation

PHYSICAL REVIEW B 93, 241401(R) (2016)

Comments

©2016 American Physical Society

Abstract

Electrostatic gating enables key functionality in modern electronic devices by altering the properties of materials. While classical electrostatics is usually sufficient to understand the effects of gating in extended systems, the inherent quantum properties of gating in nanostructures offer unexplored opportunities for materials and devices. Using first-principles calculations for Co/bilayer graphene, Co/BN/graphene, and Co/BN/benzene, as well as a simple physical model, we show that heterostructures with two-dimensional materials yield tunable magnetic proximity effects. van der Waals bonding is identified as a requirement for large electronic structure changes by gating, enabling both the magnitude and sign change of spin polarization in physisorbed graphene. The ability to electrically reverse the spin polarization of an electrode provides an alternative to using the applied magnetic field or spin transfer torque in spintronic devices, thus transforming a spin valve into a spin transistor.