Transport and localization of indirect excitons in a van der Waals heterostructure

Abstract

Long lifetimes of spatially indirect excitons (IXs), also known as interlayer excitons, allow implementing both quantum exciton systems and long-range exciton transport. Van der Waals heterostructures (HS) composed of atomically thin layers of transition-metal dichalcogenides (TMD) offer the opportunity to explore IXs in moiré superlattices. The moiré IXs in TMD HS form the materials platform for exploring the Bose-Hubbard physics and superfluid and insulating phases in periodic potentials. IX transport in TMD HS was intensively studied and diffusive IX transport with $1/e$ decay distances $d_{1/e}$ up to $\sim 3$ $\mu$m was realized. In this work, we present in MoSe${}_2$/WSe${}_2$ HS the IX long-range transport with $d_{1/e}$ exceeding 100 $\mu$m and diverging at the optical excitation resonant to spatially direct excitons. The IX long-range transport vanishes at high temperatures. With increasing IX density, IX localization, then IX long-range transport, and then IX reentrant localization is observed. The results are in qualitative agreement with the Bose-Hubbard theory of bosons in periodic potentials predicting superfluid at $N\sim 1/2$ and insulating at $N\sim 0$ and $N\sim 1$ phases for the number of bosons per site of the periodic potential $N$.

arXiv admin note: text overlap with arXiv:2204.09760

References in corpus (18)

• Light-emitting diodes by bandstructure engineering in van der Waals heterostructures
• Observation of Moiré Excitons in WSe2/WS2 Heterostructure Superlattices
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• Resonantly hybridised excitons in moiré superlattices in van der Waals heterostructures
• Moiré excitons: from programmable quantum emitter arrays to spin-orbit coupled artificial lattices
• High-temperature superfluidity with indirect excitons in van der Waals heterostructures
• Theory of optical absorption by interlayer excitons in transition metal dichalcogenide heterobilayers
• Monte Carlo study of two-dimensional Bose-Hubbard model
• Excitonic transport driven by repulsive dipolar interaction in a van der Waals heterostructure
• Drift mobility of long-living excitons in coupled GaAs quantum wells
• Electrical control of hybrid exciton transport in a van der Waals heterostructure
• Localization-Delocalization Transition of Indirect Excitons in Lateral Electrostatic Lattices
• Spatiotemporally Controlled Room Temperature Exciton Transport under Dynamic Pressure
• Towards superfluidity of dipolar excitons in a TMDC double layer
• Long-range transport of 2D excitons with acoustic waves
• Excitonic Mott insulator in a Bose-Fermi-Hubbard system of moiré ${\mathrm{WS}}_2$/${\mathrm{WSe}}_2$ heterobilayer
• Bosonic Delocalization of Dipolar Moiré Excitons
• Attractive and repulsive dipolar interaction in bilayers of indirect excitons

Cited by in corpus (6)

• 2D material exciton-polariton transport on 2D photonic crystals
• Long-distance decay-less spin transport in indirect excitons in a van der Waals heterostructure
• Electrically tunable MoSe${}_2$/WSe${}_2$ heterostructure-based quantum dot
• Long-range spatial extension of exciton states in van der Waals heterostructure
• Laterally Extended States of Interlayer Excitons in Reconstructed MoSe${}_2$/WSe${}_2$ Heterostructures
• Effective long-range attraction of moiré excitons under the influence of atomic reconstructions and anisotropic screening