Resolving spin, valley, and moiré quasi-angular momentum of interlayer excitons in WSe2/WS2 heterostructures
arXiv:1902.05887 · doi:10.1038/s41567-019-0631-4
Abstract
Moiré superlattices provide a powerful way to engineer properties of electrons and excitons in two-dimensional van der Waals heterostructures. The moiré effect can be especially strong for interlayer excitons, where electrons and holes reside in different layers and can be addressed separately. In particular, it was recently proposed that the moiré superlattice potential not only localizes interlayer exciton states at different superlattice positions, but also hosts an emerging moiré quasi-angular momentum (QAM) that periodically switches the optical selection rules for interlayer excitons at different moiré sites. Here we report the observation of multiple interlayer exciton states coexisting in a WSe2/WS2 moiré superlattice and unambiguously determine their spin, valley, and moiré QAM through novel resonant optical pump-probe spectroscopy and photoluminescence excitation spectroscopy. We demonstrate that interlayer excitons localized at different moiré sites can exhibit opposite optical selection rules due to the spatially-varying moiré QAM. Our observation reveals new opportunities to engineer interlayer exciton states and valley physics with moiré superlattices for optoelectronic and valleytronic applications.
References in corpus (31)
- Magic-angle graphene superlattices: a new platform for unconventional superconductivity
- Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
- Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
- Control of valley polarization in monolayer MoS2 by optical helicity
- MoS_2 as an ideal material for valleytronics: valley-selective circular dichroism and valley Hall effect
- Observation of Long-Lived Interlayer Excitons in Monolayer MoSe2-WSe2 Heterostructures
- Moiré Excitons in Van der Waals Heterostructures
- Signatures of moiré-trapped valley excitons in MoSe/WSe heterobilayers
- Observation of Moiré Excitons in WSe2/WS2 Heterostructure Superlattices
- k.p theory for two-dimensional transition metal dichalcogenide semiconductors
- Detecting Topological Currents in Graphene Superlattices
- Moiré excitons: from programmable quantum emitter arrays to spin-orbit coupled artificial lattices
- Evidence of Gate-Tunable Mott Insulator in Trilayer Graphene-Boron Nitride Moiré Superlattice
- In-plane Propagation of Light in Transition Metal Dichalcogenide Monolayers: Optical Selection Rules
- Topological Exciton Bands in Moiré Heterojunctions
- Probing dark excitons in atomically thin semiconductors via near-field coupling to surface plasmon polaritons
- Interlayer Exciton Optoelectronics in a 2D Heterostructure p-n Junction
- Theory of optical absorption by interlayer excitons in transition metal dichalcogenide heterobilayers
- Generic Miniband Structure of Graphene on a Hexagonal Substrate
- Control of interlayer excitons in two-dimensional van der Waals heterostructures
- Observation of fractional Chern insulators in a van der Waals heterostructure
- Splitting between Bright and Dark excitons in Transition Metal Dichalcogenide Monolayers
- Revealing the Biexciton and Trion-exciton Complexes in BN Encapsulated WSe2
- Interlayer excitons and Band Alignment in MoS/hBN/WSe van der Waals Heterostructures
- Double Indirect Interlayer Exciton in a MoSe2/WSe2 van der Waals Heterostructure
- Brightened spin-triplet interlayer excitons and optical selection rules in van der Waals heterobilayers
- Coulomb-bound four- and five-particle valleytronic states in an atomically-thin semiconductor
- Ballistic miniband conduction in a graphene superlattice
- Moiré Intralayer Excitons in a MoSe/MoS Heterostructure
- Topological Bloch Bands in Graphene Superlattices
- Interlayer excitons in MoSe/WSe heterostructures from first-principles
Cited by in corpus (36)
- Electrically tunable valley dynamics in twisted WSe/WSe bilayers
- Correlated insulator of excitons in WSe2/WS2 moiré superlattices
- Exciton-Photonics: From Fundamental Science to Applications
- Giant Valley-Zeeman Splitting from Spin-Singlet and Spin-Triplet Interlayer Excitons in WSe2/MoSe2 Heterostructure
- Excitonic and valleytronic signatures of correlated states at fractional fillings of a moiré superlattice
- Localized bright luminescence of indirect excitons and trions in MoSe/WSe van der Waals heterostructure
- Moiré and beyond in transition metal dichalcogenide twisted bilayers
- Flipping exciton angular momentum with chiral phonons in MoSe/WSe heterobilayers
- Measuring valley polarization in two-dimensional materials with second-harmonic spectroscopy
- Spatially indirect intervalley excitons in bilayer WSe2
- Light-matter interaction in van der Waals heterostructures
- Accurate Measurement of the Gap of Graphene/hBN Moiré Superlattice through Photocurrent Spectroscopy
- Voltage-controlled long-range propagation of indirect excitons in van der Waals heterostructure
- Twist angle dependent interlayer transfer of valley polarization from excitons to free charge carriers in WSe/MoSe heterobilayers
- Leaky exciton condensates in transition metal dichalcogenide moiré bilayers
- Electrically tunable topological transport of moiré polaritons
- Ultrafast electron localization and screening in a transition metal dichalcogenide
- Interlayer Exciton Valleytronics in Bilayer Heterostructures Interfaced with a Metasurface
- Harmonic to anharmonic tuning of moiré potential leading to unconventional Stark effect and giant dipolar repulsion in WS/WSe heterobilayer
- Luminescence anomaly of dipolar valley excitons in homobilayer semiconductor moiré superlattices
- Quantum Geometric Exciton Drift Velocity
- Exciton Superposition across Moiré States in a Semiconducting Moiré Superlattice
- Topological phases in N-layer ABC-graphene boron-nitride moire superlattices
- Spatiotemporal dynamics of moiré excitons in van der Waals heterostructures
- Moiré exciton condensate: nonlinear Dirac point, broken-symmetry Bloch waves and unusual optical selection rules
- Excitonic thermalization bottleneck in twisted TMD heterostructures
- Long-distance decay-less spin transport in indirect excitons in a van der Waals heterostructure
- Review: Advanced characterization of the spatial variation of moiré heterostructures and moiré excitons
- Dynamic Valley Polarization in Moire Quantum Dots
- Two dimensional semiconductors: optical and electronic properties
- Förster valley-orbit coupling and topological lattice of hybrid moiré excitons
- Twistronics and moiré superlattice physics in 2D transition metal dichalcogenides
- Optical response of alternating twisted trilayer graphene
- Engineering topological exciton structures in two-dimensional semiconductors by a periodic electrostatic potential
- Interaction enhanced inter-site hoppings for holons and interlayer exciton insulators in moiré correlated insulators
- Origin of Moiré Potentials in WS/WSe Heterobilayers: Contributions from Lattice Reconstruction and Interlayer Charge Transfer