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.

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• Electronic structures, charge transfer and charge orders in twisted transition metal dichalcogenide bilayers
• Generalized Wigner crystallization in moiré materials
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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