Brightened spin-triplet interlayer excitons and optical selection rules in van der Waals heterobilayers

Abstract

We investigate the optical properties of spin-triplet interlayer excitons in heterobilayer transition metal dichalcogenides in comparison with the spin-singlet ones. Surprisingly, the optical transition dipole of the spin-triplet exciton is found to be in the same order of magnitude to that of the spin-singlet exciton, in sharp contrast to the monolayer excitons where the spin triplet species is considered as dark compared to the singlet. Unlike the monolayer excitons whose spin-conserved (spin-flip) transition dipole can only couple to light of in-plane (out-of-plane) polarization, such restriction is removed for the interlayer excitons due to the breaking of the out-of-plane mirror symmetry. We find that as the interlayer atomic registry changes, the optical transition dipole of interlayer exciton crosses between in-plane ones of opposite circular polarization and the out-of-plane one for both the spin-triplet and spin-singlet species. As a result, excitons of both species have non-negligible coupling into photon modes of both in-plane and out-of-plane propagations, another sharp difference from the monolayers where the exciton couples predominantly into the out-of-plane propagation channel. At given atomic registry, the spin-triplet and spin-singlet excitons have distinct valley polarization selection rules, allowing the selective optical addressing of both the valley configuration and the spin singlet/triplet configuration of interlayer excitons.

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• Moiré Excitons in Van der Waals Heterostructures
• Signatures of moiré-trapped valley excitons in MoSe${}_2$/WSe${}_2$ heterobilayers
• Anomalous Interlayer Exciton Diffusion in Twist-Angle-Dependent Moiré Potentials of WS${}_2$-WSe${}_2$ Heterobilayers
• Control of interlayer excitons in two-dimensional van der Waals heterostructures
• Exciton g-factors of van der Waals heterostructures from first principles calculations
• Spin-layer locking of interlayer excitons trapped in moiré potentials
• Resolving spin, valley, and moiré quasi-angular momentum of interlayer excitons in WSe2/WS2 heterostructures
• Giant magnetic field from moiré induced Berry phase in homobilayer semiconductors
• Correlated insulator of excitons in WSe2/WS2 moiré superlattices
• Valley-selective chiral phonon replicas of dark excitons and trions in monolayer WSe2
• Giant Valley-Zeeman Splitting from Spin-Singlet and Spin-Triplet Interlayer Excitons in WSe2/MoSe2 Heterostructure
• Highly Valley-Polarized Singlet and Triplet Interlayer Excitons in van der Waals Heterostructure
• Guide to optical spectroscopy of layered semiconductors
• Moiré excitons in MoSe${}_2$-WSe${}_2$ heterobilayers and heterotrilayers
• Cavity-control of bright and dark interlayer excitons in van der Waals heterostructures
• Localized bright luminescence of indirect excitons and trions in MoSe${}_2$/WSe${}_2$ van der Waals heterostructure
• Moiré and beyond in transition metal dichalcogenide twisted bilayers
• Moiré-trapped interlayer trions in a charge-tunable WSe${}_2$/MoSe${}_2$ heterobilayer
• Magnetooptics of layered two-dimensional semiconductors and heterostructures: progress and prospects
• Interface excitons at lateral heterojunctions in monolayer semiconductors
• Electrically controlled emission from singlet and triplet exciton species in atomically thin light emitting diodes
• Intercell Moiré Exciton Complexes in Electron Lattices
• Optical control of valley Zeeman effect through many-exciton interactions
• Localization and interaction of interlayer excitons in MoSe${}_2$/WSe${}_2$ heterobilayers
• Optical dipole orientation of interlayer excitons in MoSe${}_2$-WSe${}_2$ heterostacks
• Evidence for Exciton Crystals in a 2D Semiconductor Heterotrilayer
• Room-temperature bipolar valleytronic transistor in MoS2/WSe2 heterostructures
• Theory of moiré localized excitons in transition-metal dichalcogenide heterobilayers
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• Relaxation effects in twisted bilayer molybdenum disulfide: structure, stability, and electronic properties
• Spatially indirect intervalley excitons in bilayer WSe2
• Dynamic polarization of electron spins interacting with nuclei in semiconductor nanostructures
• Transport and localization of indirect excitons in a van der Waals heterostructure
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• Interlayer Exciton Valleytronics in Bilayer Heterostructures Interfaced with a Metasurface
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• Luminescence anomaly of dipolar valley excitons in homobilayer semiconductor moiré superlattices
• Twist versus heterostrain control of optical properties of moiré exciton minibands
• Interlayer donor-acceptor pair excitons in MoSe2/WSe2 moiré heterobilayer
• Quadrupolar Excitons in MoSe${}_2$ Bilayers
• Quadrupolar and Dipolar Excitons in Bilayer 2$H$-MoSe${}_2$
• Electromagnetic field assisted exciton diffusion in moiré superlattices
• Electrically controlled emission from triplet charged excitons in atomically thin heterostructures
• Anomalous magneto-optical response and chiral interface of dipolar excitons at twisted valleys
• Long-distance decay-less spin transport in indirect excitons in a van der Waals heterostructure
• Two dimensional semiconductors: optical and electronic properties
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• Interplay of trapped species and absence of electron capture in Moiré heterobilayers
• Dipolar interactions enhanced by two-dimensional dielectric screening in few-layer van der Waals structures
• Twistronics and moiré superlattice physics in 2D transition metal dichalcogenides
• Förster valley-orbit coupling and topological lattice of hybrid moiré excitons
• Optically and magnetically addressable valley pseudospin of interlayer excitons in bilayer MoS2
• Exciton Transport under Periodic Potential in MoSe2/WSe2 Heterostructures
• Hierarchical Disorder in Moiré Exciton Photoluminescence Probed by Spectral-Descriptor Correlations
• Enhancement of the WS${}_2$ A${}_{1\text{g}}$ Raman Mode in MoS${}_2$/WS${}_2$ Heterostructures
• Long-range spatial extension of exciton states in van der Waals heterostructure
• Long-lived populations of momentum- and spin-indirect excitons in monolayer WSe${}_2$
• Intersubband electric dipole spin resonance in transition metal dichalcogenide heterobilayers
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