[en] Quantum Hall (QH) and quantum spin Hall (QSH) phases have very different edge states and, when going from one phase to the other, the direction of one edge state must be reversed. We study this phenomenon in graphene in the presence of a strong perpendicular magnetic field on top of a spin-orbit (SO)-induced QSH phase. We show that, below the SO gap, the QSH phase is virtually unaffected by the presence of the magnetic field. Above the SO gap, the QH phase is restored. An electrostatic gate placed on top of the system allows the creation of a QSH-QH junction which is characterized by the existence of a spin-polarized chiral state, propagating along the topological interface. We find that such a setup naturally provides an extremely sensitive spin-polarized current switch which could pave the way to novel spin-based electronic devices.
Disciplines :
Physics
Author, co-author :
Shevtsov, Oleksii; CEA INAC UJF Grenoble 1, SPSMS UMR E 9001, F-38054 Grenoble, France.
Carmier, Pierre; CEA INAC UJF Grenoble 1, SPSMS UMR E 9001, F-38054 Grenoble, France.
Petitjean, Cyril ; Université de Liège - ULiège > Département de physique > Physique quantique statistique
Groth, Christoph; CEA INAC UJF Grenoble 1, SPSMS UMR E 9001, F-38054 Grenoble, France.
Carpentier, David; Ecole Normale Super Lyon, CNRS Lab Phys, Lyon, France.
Waintal, Xavier; CEA INAC UJF Grenoble 1, SPSMS UMR E 9001, F-38054 Grenoble, France.
Language :
English
Title :
Graphene-Based Heterojunction between Two Topological Insulators
Publication date :
2012
Journal title :
Physical Review X
ISSN :
2160-3308
Publisher :
Amer Physical Soc, College Pk, United States - Maryland
Volume :
2
Issue :
3
Pages :
031004-10
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
STREP ConceptGraphene, EC [ERC MesoQMC] ANR Grant [2010-IsoTop]
Commentary :
This work was supported by STREP ConceptGraphene, EC Contract No. ERC MesoQMC, and ANR Grant No. 2010-IsoTop.
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