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arXiv · 1508.01249

Spin- and valley- coupled electronic states in monolayer WSe2 on bilayer graphene

K. Sugawara·T. Sato·Y. Tanaka·S. Souma·T. Takahashi
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Abstract

We have fabricated a high-quality monolayer WSe2 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 Brillounin-zone corner in contrast to the indirect nature of gap in bulk WSe2, 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 WSe2 to develop advanced devices based with the coupling of spin- and valley-degrees of freedom.

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K. Sugawara, T. Sato, Y. Tanaka, S. Souma, T. Takahashi. 2015-08-06. Spin- and valley- coupled electronic states in monolayer WSe2 on bilayer graphene. https://doi.org/10.1063/1.4928658

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