Anomalous Interlayer Exciton Diffusion in Twist-Angle-Dependent Moiré Potentials of WS${}_2$-WSe${}_2$ Heterobilayers

Abstract

The nanoscale periodic potentials introduced by moiré patterns in semiconducting van der Waals (vdW) heterostructures provide a new platform for designing exciton superlattices. To realize these applications, a thorough understanding of the localization and delocalization of interlayer excitons in the moiré potentials is necessary. Here, we investigated interlayer exciton dynamics and transport modulated by the moiré potentials in WS${}_2$-WSe${}_2$ heterobilayers in time, space, and momentum domains using transient absorption microscopy combined with first-principles calculations. Experimental results verified the theoretical prediction of energetically favorable K-Q interlayer excitons and unraveled exciton-population dynamics that was controlled by the twist-angle-dependent energy difference between the K-Q and K-K excitons. Spatially- and temporally-resolved exciton-population imaging directly visualizes exciton localization by twist-angle-dependent moiré potentials of ~100 meV. Exciton transport deviates significantly from normal diffusion due to the interplay between the moiré potentials and strong many-body interactions, leading to exciton-density- and twist-angle-dependent diffusion length. These results have important implications for designing vdW heterostructures for exciton and spin transport as well as for quantum communication applications.

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Cited by in corpus (56)

• One-Dimensional Moiré Excitons in Transition-Metal Dichalcogenide Heterobilayers
• Enhanced Light-Matter Interaction in Two-Dimensional Transition Metal Dichalcogenides
• Moiré Potential Impedes Interlayer Exciton Diffusion in van der Waals Heterostructures
• Excitonic transport driven by repulsive dipolar interaction in a van der Waals heterostructure
• Electronic structures, charge transfer and charge orders in twisted transition metal dichalcogenide bilayers
• Shedding Light on Moire Excitons: A First-Principles Perspective
• Diffusivity Reveals Three Distinct Phases of Interlayer Excitons in MoSe2/WSe2 Heterobilayers
• Hyperspectral imaging of excitons within a moiré unit-cell with a sub-nanometer electron probe
• Exciton optics, dynamics and transport in atomically thin semiconductors
• Roadmap for Photonics with 2D Materials
• Nonclassical Exciton Diffusion in Monolayer WSe2
• Moiré and beyond in transition metal dichalcogenide twisted bilayers
• Moiré-trapped interlayer trions in a charge-tunable WSe${}_2$/MoSe${}_2$ heterobilayer
• Interlayer Exciton Diode and Transistor
• Localization and interaction of interlayer excitons in MoSe${}_2$/WSe${}_2$ heterobilayers
• Ultrafast dynamics of bright and dark excitons in monolayer WSe${}_2$ and heterobilayer WSe${}_2$/MoS${}_2$
• Microscopic origin of anomalous interlayer exciton transport in van der Waals heterostructures
• Spatially indirect intervalley excitons in bilayer WSe2
• Spin/valley coupled dynamics of electrons and holes at the ${\text{MoS}}_2-{\text{MoSe}}_2$ interface
• Transport and localization of indirect excitons in a van der Waals heterostructure
• Exciton-exciton interactions in van der Waals heterobilayers
• Mott-moiré excitons
• Twist angle dependent interlayer transfer of valley polarization from excitons to free charge carriers in WSe${}_2$/MoSe${}_2$ heterobilayers
• Decomposition and embedding in the stochastic $GW$ self-energy
• Lattice reconstruction in MoSe${}_2$-WSe${}_2$ heterobilayers synthesized by chemical vapor deposition
• Two-Dimensional Moiré Polaronic Electron Crystals
• Harmonic to anharmonic tuning of moiré potential leading to unconventional Stark effect and giant dipolar repulsion in WS${}_2$/WSe${}_2$ heterobilayer
• Quantum Geometric Exciton Drift Velocity
• Electrically tunable dipolar interactions between layer-hybridized excitons
• Non-bosonic moiré excitons
• Twisted MoSe2 Homobilayer Behaving as a Heterobilayer
• Nonlinear exciton drift in piezoelectric two-dimensional materials
• 2D material exciton-polariton transport on 2D photonic crystals
• Spatiotemporal dynamics of moiré excitons in van der Waals heterostructures
• Optical Signatures of Moiré Trapped Biexcitons
• Engineering the strain and interlayer excitons of 2D materials via lithographically engraved hexagonal boron nitride
• Time-Domain Signatures of Distinct Correlated Insulators in a Moiré Superlattice
• Deformable Molecular Crystal on 2D Crystal: A New Way to Build Nanoscale Periodic Trapping Sites for Interlayer Excitons
• Trapping Interlayer Excitons in van der Waals Heterostructures by Potential Arrays
• Two dimensional semiconductors: optical and electronic properties
• Viscous hydrodynamics of excitons in van der Waals heterostructures
• Twistronics and moiré superlattice physics in 2D transition metal dichalcogenides
• Stability of Wigner crystals and Mott insulators in twisted moiré structures
• Spatial filtering of interlayer exciton ground state in WSe2/MoS2 heterobilayer
• Impact of an electron Wigner crystal on exciton propagation
• Non-Equilibrium First-Order Exciton Mott Transition at Monolayer Lateral Heterojunctions Visualized by Ultrafast Microscopy
• Polariton transport in 2D semiconductors: Phonon-mediated transitions between ballistic, superdiffusive and exciton-limited regimes
• Purely electronic model for exciton-polaron formation in moiré heterostructures
• Dual-Polarization SHG Interferometry for Imaging Antiparallel Domains and Stacking Angles of 2D Heterocrystals
• Fast Interlayer Energy Transfer from the Lower Bandgap MoS2 to the Higher Bandgap WS2
• Understanding the Effects of Dielectric Property, Separation Distance, and Band Alignment on Interlayer Excitons in 2D Hybrid MoS2/WSe2 Heterostructures
• Propagating Collective Spin-valley Modes in Twisted WSe2
• Long-range spatial extension of exciton states in van der Waals heterostructure
• Geometry-Driven Moiré Engineering in Twisted Bilayers of High-Pseudospin Fermions
• Quantum Geometry Driven Finite-Momentum Exciton Fluctuations in Flat-Band Systems
• Quantum siphoning of finely spaced interlayer excitons in reconstructed MoSe2/WSe2 heterostructures