Electrical spin manipulation in graphene nanostructures

作     者：R. Ortiz N. A. García-Martínez J. L. Lado J. Fernández-Rossier 

作者机构：Departamento de Física Aplicada Universidad de Alicante 03690 Spain QuantaLab International Iberian Nanotechnology Laboratory (INL) Avenida Mestre José Veiga 4715-330 Braga Portugal Institute for Theoretical Physics ETH Zurich 8093 Zurich Switzerland 

出 版 物：《Physical Review B》 (Phys. Rev. B)

年 卷 期：2018年第97卷第19期

页      面：195425-195425页

核心收录：

基　　金：European Regional Development Fund, FEDER Fundació Catalana de Trasplantament, FCT, (PTDC/FIS-NAN/4662/2014, PTDC/FIS-NAN/3668/2014) MINECO-Spain, (MAT2016-78625-C2) Seventh Framework Programme, FP7, (607904) 

主　　题：Rashba coupling Spin-orbit coupling Spintronics Graphene Nanostructures Hubbard model Tight-binding model 

摘      要：We propose a mechanism to drive singlet-triplet spin transitions electrically in a wide class of graphene nanostructures that present pairs of in-gap zero modes, localized at opposite sublattices. Examples are rectangular nanographenes with short zigzag edges, armchair ribbon heterojunctions with topological in-gap states, and graphene islands with sp3 functionalization. The interplay between the hybridization of zero modes and the Coulomb repulsion leads to symmetric exchange interaction that favors a singlet ground state. Application of an off-plane electric field to the graphene nanostructure generates an additional Rashba spin-orbit coupling, which results in antisymmetric exchange interaction that mixes S=0 and S=1 manifolds. We show that modulation in time of either the off-plane electric field or the applied magnetic field permits performing electrically driven spin resonance in a system with very long spin-relaxation times.