Harmonic to anharmonic tuning of moiré potential leading to unconventional Stark effect and giant dipolar repulsion in WS/WSe heterobilayer
arXiv:2307.12880 · doi:10.1038/s41467-023-40329-3
Abstract
Excitonic states trapped in harmonic moiré wells of twisted heterobilayers is an intriguing testbed. However, the moiré potential is primarily governed by the twist angle, and its dynamic tuning remains a challenge. Here we demonstrate anharmonic tuning of moiré potential in a WS/WSe heterobilayer through gate voltage and optical power. A gate voltage can result in a local in-plane perturbing field with odd parity around the high-symmetry points. This allows us to simultaneously observe the first (linear) and second (parabolic) order Stark shift for the ground state and first excited state, respectively, of the moiré trapped exciton - an effect opposite to conventional quantum-confined Stark shift. Depending on the degree of confinement, these excitons exhibit up to twenty-fold gate-tunability in the lifetime ( to ns). Also, exciton localization dependent dipolar repulsion leads to an optical power-induced blueshift of 1 meV/W - a five-fold enhancement over previous reports.
arXiv commentAccepted in Nature Communications
References in corpus (30)
- Observation of tightly bound trions in monolayer MoS2
- Ultrafast Charge Transfer in Atomically Thin MoS2/WS2 Heterostructures
- 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
- Electroluminescence and photocurrent generation from atomically sharp WSe2/MoS2 heterojunction p-n diodes
- Resonantly hybridised excitons in moiré superlattices in van der Waals heterostructures
- Determination of band alignment in the single layer MoS2/WSe2 heterojunction
- Abundance of correlated insulating states at fractional fillings of WSe/WS moiré superlattices
- Ultraflat bands and shear solitons in Moiré patterns of twisted bilayer transition metal dichalcogenides
- Exciton-exciton annihilation in MoSe2 monolayers
- Anomalous Interlayer Exciton Diffusion in Twist-Angle-Dependent Moiré Potentials of WS-WSe Heterobilayers
- Theory of optical absorption by interlayer excitons in transition metal dichalcogenide heterobilayers
- Interlayer exciton dynamics in a dichalcogenide monolayer heterostructure
- Twist Angle Dependent Interlayer Exciton Lifetimes in van der Waals Heterostructures
- Brightened spin-triplet interlayer excitons and optical selection rules in van der Waals heterobilayers
- Exciton correlations in coupled quantum wells and their luminescence blue shift
- Resolving spin, valley, and moiré quasi-angular momentum of interlayer excitons in WSe2/WS2 heterostructures
- Excitonic transport driven by repulsive dipolar interaction in a van der Waals heterostructure
- Stark effect spectroscopy of mono- and few-layer MoS
- Origin and Evolution of Ultraflatbands in Twisted Bilayer Transition Metal Dichalcogenides: Realization of Triangular Quantum Dot Array
- Discrete Interactions between a few Interlayer Excitons Trapped at a MoSe-WSe Heterointerface
- Excitonic and valleytronic signatures of correlated states at fractional fillings of a moiré superlattice
- Suppressed out-of-plane polarizability of free excitons in monolayer WSe
- Anomalous Stark Shift of Excitonic Complexes in Monolayer Semiconductor
- Inter-layer charge transport controlled by exciton-trion coherent coupling
- Optical signature of cascade transitions between moiré interlayer excitons
- Trion-trion annihilation in monolayer WS
- Dark-state impact on the exciton recombination of WS2 monolayers as revealed by multi-time-scale pump-and-probe spectroscopy
- Confined-state physics and signs of fermionization of moiré excitons in WSe/MoSe heterobilayers