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Title: Spin- and valley-coupled electronic states in monolayer WSe{sub 2} on bilayer graphene

We have fabricated a high-quality monolayer WSe{sub 2} film on bilayer graphene by epitaxial growth and revealed the electronic states by spin- and angle-resolved photoemission spectroscopy. We observed a direct energy gap at the Brillouin-zone corner in contrast to the indirect nature of gap in bulk WSe{sub 2}, which is attributed to the lack of interlayer interaction and the breaking of space-inversion symmetry in monolayer film. A giant spin splitting of ∼0.5 eV, which is the largest among known monolayer transition-metal dichalcogenides, is observed in the energy band around the zone corner. The present results suggest a high potential applicability of WSe{sub 2} to develop advanced devices based with the coupling of spin- and valley-degrees of freedom.
Authors:
;  [1] ; ;  [2] ;  [1] ;  [3]
  1. WPI Research Center, Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)
  2. Department of Physics, Tohoku University, Sendai 980-8578 (Japan)
  3. (Japan)
Publication Date:
OSTI Identifier:
22489107
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 7; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BRILLOUIN ZONES; COUPLING; DEGREES OF FREEDOM; ENERGY GAP; EPITAXY; FILMS; GRAPHENE; LAYERS; PHOTOELECTRON SPECTROSCOPY; SPIN; SYMMETRY; TRANSITION ELEMENTS