Local Spectroscopic Characterization of Spin and Layer Polarization in WSe${}_2$

Abstract

We report scanning tunneling microscopy (STM) and spectroscopy (STS) measurements of monolayer and bilayer WSe${}_2$. We measure a band gap of 2.21 $\pm$ 0.08 eV in monolayer WSe${}_2$, which is much larger than the energy of the photoluminescence peak indicating a large excitonic binding energy. We additionally observe significant electronic scattering arising from atomic-scale defects. Using Fourier transform STS (FT-STS), we map the energy versus momentum dispersion relations for monolayer and bilayer WSe${}_2$. Further, by tracking allowed and forbidden scattering channels as a function of energy we infer the spin texture of both the conduction and valence bands. We observe a large spin-splitting of the valence band due to strong spin-orbit coupling, and additionally observe spin-valley-layer coupling in the conduction band of bilayer WSe${}_2$.

5 pages, 4 figures

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• Density-Dependent Quantum Hall States and Zeeman Splitting in Monolayer and Bilayer WSe${}_2$
• Observation of intervalley quantum interference in epitaxial monolayer WSe2
• Spin-Conserving Resonant Tunneling in Twist-Controlled WSe2-hBN-WSe2 Heterostructures
• Symmetry-forbidden intervalley scattering by atomic defects in monolayer transition-metal dichalcogenides
• Every-other-layer Dipolar Excitons in a Spin-Valley locked Superlattice
• Landau levels and Shubnikov-de Haas oscillations in monolayer transition metal dichalcogenide semiconductors
• Ab initio Ultrafast Spin Dynamics in Solids
• Evidence of itinerant holes for long-range magnetic order in tungsten diselenide semiconductor with vanadium dopants
• Symmetry breaking and spin-orbit coupling for individual vacancy-induced in-gap states in MoS2 monolayers
• Intra-Domain Periodic Defects in Monolayer MoS${}_2$
• Atomistic $T$-matrix theory of disordered 2D materials: Bound states, spectral properties, quasiparticle scattering, and transport
• Orbital-dependent quasiparticle scattering interference in 3R-NbS2
• Liquid-solid surface phase transformation of fluorinated fullerene on monolayer tungsten diselenide
• Local characterization and engineering of proximitized correlated states in graphene-NbSe${}_2$ vertical heterostructures
• Spin susceptibility in interacting two-dimensional semiconductors and bilayer systems at first order: Kohn anomalies and spin density wave ordering
• Efficient $GW$ band structure calculations using Gaussian basis functions and application to atomically thin transition-metal dichalcogenides