Cysne, Tarik P., Ferreira, Aires orcid.org/0000-0001-6017-8669 and Rappoport, Tatiana G. (2018) Crystal-field effects in graphene with interface-induced spin-orbit coupling. Phys. Rev. B. 045407.
Abstract
We consider theoretically the influence of crystalline fields on the electronic structure of graphene placed on a layered material with reduced symmetry and large spin-orbit coupling (SOC). We use a perturbative procedure combined with the Slater-Koster method to derive the low-energy effective Hamiltonian around the $K$ points and estimate the magnitude of the effective couplings. Two simple models for the envisaged graphene-substrate hybrid bilayer are considered, in which the relevant atomic orbitals hybridize with either top or hollow sites of the graphene honeycomb lattice. In both cases, the interlayer coupling to a crystal-field-split substrate is found to generate highly anisotropic proximity spin-orbit interactions, including in-plane 'spin-valley' coupling. Interestingly, when an anisotropic intrinsic-type SOC becomes sizeable, the bilayer system is effectively a quantum spin Hall insulator characterized by in-plane helical edge states robust against Bychkov-Rashba effect. Finally, we discuss the type of substrate required to achieve anisotropic proximity-induced SOC and suggest possible candidates to further explore crystal field effects in graphene-based heterostructures.
Metadata
Authors/Creators: |
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Copyright, Publisher and Additional Information: | ©2018 American Physical Society. 9 pages, 5 figures | ||||
Keywords: | graphene, spin orbit effects, crystal field effects | ||||
Dates: |
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Institution: | The University of York | ||||
Academic Units: | The University of York > Faculty of Sciences (York) > Physics (York) | ||||
Funding Information: |
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Depositing User: | Pure (York) | ||||
Date Deposited: | 10 Jul 2018 14:20 | ||||
Last Modified: | 04 Feb 2024 00:55 | ||||
Published Version: | https://doi.org/10.1103/PhysRevB.98.045407 | ||||
Status: | Published | ||||
Refereed: | Yes | ||||
Identification Number: | https://doi.org/10.1103/PhysRevB.98.045407 |