Proximity-induced magnetization in graphene: Towards efficient spin gating

Authors

Mihovil Bosnar, Institute Ruder BoskovicFollow
Ivor Lončarić, Institute Ruder Boskovic
P. Lazić, Institute Ruder Boskovic
Kirill Belashchenko, University of Nebraska - LincolnFollow
Igor Žutić, University at Buffalo, The State University of New York

ORCID IDs

Ivor Lončarić https://orcid.org/0000-0002-3234-0179

K. D. Belashchenko https://orcid.org/0000-0002-8518-1490

Document Type

Article

Date of this Version

11-13-2020

Citation

PHYSICAL REVIEW MATERIALS 4, 114006 (2020)

DOI: 10.1103/PhysRevMaterials.4.114006

Comments

©2020 American Physical Society. Used by permission.

Abstract

Gate-tunable spin-dependent properties could be induced in graphene at room temperature through the magnetic proximity effect by placing it in contact with a metallic ferromagnet. Because strong chemical bonding with the metallic substrate makes gating ineffective, an intervening passivation layer is needed. Previously considered passivation layers result in a large shift of the Dirac point away from the Fermi level, so that unrealistically large gate fields are required to tune the spin polarization in graphene (Gr). We show that a monolayer of Au or Pt used as the passivation layer between Co and graphene brings the Dirac point closer to the Fermi level. In the Co/Pt/Gr system the proximity-induced spin polarization in graphene and its gate control are strongly enhanced by the presence of a surface band near the Fermi level. Furthermore, the shift of the Dirac point could be eliminated entirely by selecting submonolayer coverage in the passivation layer. Our findings open a path towards experimental realization of an optimized two-dimensional system with gate-tunable spin-dependent properties.