Theory of intervalley Coulomb interactions in monolayer transition-metal dichalcogenides

Abstract

Exciton optical transitions in transition-metal dichalcogenides offer unique opportunities to study rich many-body physics. Recent experiments in monolayer WSe${}_2$ and WS${}_2$ have shown that while the low-temperature photoluminescence from neutral excitons and three-body complexes is suppressed in the presence of elevated electron densities or strong photoexcitation, new dominant peaks emerge in the low-energy side of the spectrum. I present a theory that elucidates the nature of these optical transitions showing the role of the intervalley Coulomb interaction. After deriving a compact dynamical form for the Coulomb potential, I calculate the self-energy of electrons due to their interaction with this potential. For electrons in the upper valleys of the spin-split conduction band, the self energy includes a moderate redshift due to exchange, and most importantly, a correlation-induced virtual state in the band-gap. The latter sheds light on the origin of the luminescence in monolayer WSe${}_2$ and WS${}_2$ in the presence of pronounced many-body interactions.

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• Valley polarization in MoS2 monolayers by optical pumping
• The Valley Hall Effect in MoS2 Transistors
• Light-emitting diodes by bandstructure engineering in van der Waals heterostructures
• k.p theory for two-dimensional transition metal dichalcogenide semiconductors
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• Exciton band structure of monolayer MoS2
• Splitting between Bright and Dark excitons in Transition Metal Dichalcogenide Monolayers
• Polarization and time-resolved photoluminescence spectroscopy of excitons in MoSe2 monolayers
• Three-particle Complexes in Two-Dimensional Semiconductors
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Cited by in corpus (27)

• Excitons in atomically thin transition metal dichalcogenides
• Charged excitons in monolayer WSe${}_2$: experiment and theory
• Neutral and Charged Inter-Valley Biexcitons in Monolayer MoSe${}_2$
• Control of the Exciton Radiative Lifetime in van der Waals Heterostructures
• Magnetic Proximity Effects in Transition-Metal Dichalcogenides: Converting Excitons
• Exciton-phonon coupling in MoSe2 monolayers
• Probing the spin-polarized electronic band structure in monolayer transition metal dichalcogenides by optical spectroscopy
• Spin-Polarized Electrons in Monolayer MoS${}_2$
• Probing Many-Body Interactions in Monolayer Transition-Metal Dichalcogenides
• Imaging Spin Dynamics in Monolayer WS2 by Time-Resolved Kerr Rotation Microscopy
• Dynamical screening in monolayer transition-metal dichalcogenides and its manifestations in the exciton spectrum
• Marrying excitons and plasmons in monolayer transition-metal dichalcogenides
• Strongly interaction-enhanced valley magnetic response in monolayer WSe2
• Dark trions and biexcitons in WS2 and WSe2 made bright by e-e scattering
• Inter-valley dark trion states with spin lifetimes of 150 ns in WSe${}_2$
• Hexcitons and oxcitons in monolayer WSe${}_2$
• Exciton valley depolarization in monolayer transition-metal dichalcogenides
• Optically Probing Tunable Band Topology in Atomic Monolayers
• Frequency-dependent substrate screening of excitons in atomically thin transition metal dichalcogenide semiconductors
• Valley Dynamics of Excitons in Monolayer Dichalcogenides
• Direct Measurement of Biexcitons in Monolayer WS2
• Composite excitonic states in doped semiconductors
• Charge-carrier complexes in monolayer semiconductors
• Optical fingerprint of non-covalently functionalized transition metal dichalcogenides
• Effect of intravalley and intervalley electron-hole exchange on the nonlinear optical response of monolayer MoSe${}_2$
• Energy shifts and broadening of excitonic resonances in electrostatically-doped semiconductors
• Strong intervalley correlation induced a magnetic order transition in monolayer ${\text{MoS}}_2$