Excitonic and valleytronic signatures of correlated states at fractional fillings of a moiré superlattice

Abstract

Moiré superlattices are excellent platforms to realize strongly correlated quantum phenomena, such as Mott insulation and superconductivity. In particular, recent research has revealed stripe phases and generalized Wigner crystals at fractional fillings of moiré superlattices. But these experiments have not focused on the influence of electronic crystallization on the excitonic and valleytronic properties of the superlattices. Here we report excitonic and valleytronic signatures of correlated states at fractional fillings in a WSe${}_2$/WS${}_2$ moiré superlattice. We observe reflection spectral modulation of three intralayer moiré excitons at filling factors $\nu$ = 1/3 and 2/3. We also observe luminescence spectral modulation of interlayer trions at around a dozen fractional filling factors, including $\nu$ = -3/2, 1/4, 1/3, 2/5, 2/3, 6/7, 5/3. In addition, the valley polarization of interlayer trions is noticeably suppressed at some fractional fillings. These results demonstrate a new regime of light-matter interactions, in which electron crystallization significantly modulates the absorption, emission, and valley dynamics of the excitonic states in a moiré superlattice.

References in corpus (35)

• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• Control of valley polarization in monolayer MoS2 by optical helicity
• Valley polarization in MoS2 monolayers by optical pumping
• Moire bands in twisted double-layer graphene
• MoS_2 as an ideal material for valleytronics: valley-selective circular dichroism and valley Hall effect
• Tuning superconductivity in twisted bilayer graphene
• Excitons in atomically thin transition metal dichalcogenides
• Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene
• Superconductors, Orbital Magnets, and Correlated States in Magic Angle Bilayer Graphene
• Intrinsic quantized anomalous Hall effect in a moiré heterostructure
• Moiré Excitons in Van der Waals Heterostructures
• Signatures of moiré-trapped valley excitons in MoSe${}_2$/WSe${}_2$ heterobilayers
• Observation of Moiré Excitons in WSe2/WS2 Heterostructure Superlattices
• Optical detection of Mott and generalized Wigner crystal states in WSe2/WS2 moiré superlattices
• Magic continuum in twisted bilayer WSe2
• Resonantly hybridised excitons in moiré superlattices in van der Waals heterostructures
• Graphene Bilayers with a Twist
• Kramers-Kronig constrained variational analysis of optical spectra
• Hubbard model physics in transition metal dichalcogenide moiré bands
• Tunable Correlated Chern Insulator and Ferromagnetism in Trilayer Graphene/Boron Nitride Moiré Superlattice
• Signatures of Gate-Tunable Superconductivity in Trilayer Graphene/Boron Nitride Moiré Superlattice
• Abundance of correlated insulating states at fractional fillings of WSe${}_2$/WS${}_2$ moiré superlattices
• Evidence of Gate-Tunable Mott Insulator in Trilayer Graphene-Boron Nitride Moiré Superlattice
• Moiré superlattice in a MoSe${}_2$/hBN/MoSe${}_2$ heterostructure: from coherent coupling of inter- and intra-layer excitons to correlated Mott-like states of electrons
• Valley excitons in two-dimensional semiconductors
• Correlated Insulating States at Fractional Fillings of the WS2/WSe2 Moiré Lattice
• One-Dimensional Moiré Excitons in Transition-Metal Dichalcogenide Heterobilayers
• Interlayer hybridization and moiré superlattice minibands for electrons and excitons in heterobilayers of transition-metal dichalcogenides
• Moiré quantum chemistry: charge transfer in transition metal dichalcogenide superlattices
• Resolving spin, valley, and moiré quasi-angular momentum of interlayer excitons in WSe2/WS2 heterostructures
• Electronic structures, charge transfer and charge orders in twisted transition metal dichalcogenide bilayers
• Generalized Wigner crystallization in moiré materials
• Nanoscale Conductivity Imaging of Correlated Electronic States in WSe2/WS2 Moiré Superlattices
• Landau-quantized excitonic absorption and luminescence in a monolayer valley semiconductor

Cited by in corpus (37)

• Observation of integer and fractional quantum anomalous Hall effects in twisted bilayer MoTe2
• Programming Correlated Magnetic States via Gate Controlled Moiré Geometry
• Correlated interlayer exciton insulator in double layers of monolayer WSe2 and moiré WS2/WSe2
• Correlated insulator of excitons in WSe2/WS2 moiré superlattices
• Exciton optics, dynamics and transport in atomically thin semiconductors
• Topological Phases in AB-Stacked MoTe${}_2$/WSe${}_2$: ${\mathbb{Z}}_2$ Topological Insulators, Chern Insulators, and Topological Charge Density Waves
• Moiré-trapped interlayer trions in a charge-tunable WSe${}_2$/MoSe${}_2$ heterobilayer
• Quadrupolar Excitons and Hybridized Interlayer Mott Insulator in a Trilayer Moiré Superlattice
• Intercell Moiré Exciton Complexes in Electron Lattices
• Optical read-out of Coulomb staircases in a moiré superlattice via trapped interlayer trions
• Hofstadter states and reentrant charge order in a semiconductor moiré lattice
• Kagome chiral spin liquid in transition metal dichalcogenide moiré bilayers
• Interaction range and temperature dependence of symmetry breaking in strongly correlated two-dimensional moiré transition metal dichalcogenide bilayers
• 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
• Distinct moiré textures of in-plane electric polarizations for distinguishing moiré origins in homobilayers
• Charge Density Wave Activated Excitons in TiSe${}_2$-MoSe${}_2$ Heterostructures
• Interlayer donor-acceptor pair excitons in MoSe2/WSe2 moiré heterobilayer
• Doping a Wigner-Mott insulator: Exotic charge orders in transition-metal dichalcogenide moiré heterobilayers
• Competing Generalized Wigner Crystal States in Moiré Heterostructures
• Realizing a tunable honeycomb lattice in ABBA-stacked twisted double bilayer WSe${}_2$
• Coherent Modulation of Two-Dimensional Moiré States with On-Chip THz Waves
• Time-Domain Signatures of Distinct Correlated Insulators in a Moiré Superlattice
• Light-Induced Ferromagnetism in Moiré Superlattices
• Exciton and light induced ferromagnetism from doping a moiré Mott insulator
• Phonons of electronic crystals in two-dimensional semiconductor moiré patterns
• Local Sensing of Correlated Electrons in Dual-moiré Heterostructures using Dipolar Excitons
• Twistronics and moiré superlattice physics in 2D transition metal dichalcogenides
• Melting of electronic and excitonic crystals in 2D semiconductor moiré patterns: a perspective from the Lindemann criterion
• Dynamic generation of spin spirals of moiré trapped carriers via exciton mediated spin interactions
• Chiral phonons of honeycomb-type bilayer Wigner crystals
• Interlayer couplings in homobilayer structures of MSi2X4 (M = Mo/W, X = N/P/As)
• Optical signatures of -1/3 fractional quantum anomalous Hall state in twisted MoTe2
• Non-local interactions and supersolidity of moiré excitons
• Electronic phonon-induced magnetism in moiré Mott-Wigner crystals
• Origin of Moiré Potentials in WS${}_2$/WSe${}_2$ Heterobilayers: Contributions from Lattice Reconstruction and Interlayer Charge Transfer
• Interaction enhanced inter-site hoppings for holons and interlayer exciton insulators in moiré correlated insulators