Large spin relaxation anisotropy and valley-Zeeman spin-orbit coupling in WSe2 /graphene/ h -BN heterostructures
Zihlmann, Simon (Universität Basel. Department of Physics)
Cummings, Aron (Institut Català de Nanociència i Nanotecnologia)
Garcia, José H. (Institut Català de Nanociència i Nanotecnologia)
Kedves, Máté (Budapesti Müszaki és Gazdaságtudományi Egyetem.Department of Physics)
Watanabe, Kenji (National Institute for Material Science (Tsukuba, Japan))
Taniguchi, Takashi (National Institute for Material Science (Tsukuba, Japan))
Schönenberger, Christian (Universität Basel. Department of Physics)
Makk, Péter (Universität Basel. Department of Physics)

Date:	2018
Abstract:	Large spin-orbital proximity effects have been predicted in graphene interfaced with a transition-metal dichalcogenide layer. Whereas clear evidence for an enhanced spin-orbit coupling has been found at large carrier densities, the type of spin-orbit coupling and its relaxation mechanism remained unknown. We show an increased spin-orbit coupling close to the charge neutrality point in graphene, where topological states are expected to appear. Single-layer graphene encapsulated between the transition-metal dichalcogenide WSe2 and h-BN is found to exhibit exceptional quality with mobilities as high as 1×105 cm2 V-1 s-1. At the same time clear weak antilocalization indicates strong spin-orbit coupling, and a large spin relaxation anisotropy due to the presence of a dominating symmetric spin-orbit coupling is found. Doping-dependent measurements show that the spin relaxation of the in-plane spins is largely dominated by a valley-Zeeman spin-orbit coupling and that the intrinsic spin-orbit coupling plays a minor role in spin relaxation. The strong spin-valley coupling opens new possibilities in exploring spin and valley degree of freedom in graphene with the realization of new concepts in spin manipulation.
Grants:	European Commission 696656 Ministerio de Economía y Competitividad SEV-2013-0295
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Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Published in:	Physical review B, Vol. 97, issue 7 (Feb. 2018) , p. 75434, ISSN 2469-9969

DOI: 10.1103/PhysRevB.97.075434

Postprint 12 p, 1.1 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles