Key role of the moire potential for the quasi-condensation of interlayer excitons in van der Waals heterostructures

Abstract

Interlayer excitons confined in bilayer heterostructures of transition metal dichalcogenides (TMDs) offer a promising route to implement two-dimensional dipolar superfluids. Here, we study the experimental conditions necessary for the realisation of such collective state. Particularly, we show that the moire potential inherent to TMD bilayers yields an exponential increase of the excitons effective mass. To allow for exciton superfluidity at sizeable temperatures it is then necessary to intercalate a high-$\kappa$ dielectric between the monolayers confining electrons and holes. Thus the moire lattice depth is sufficiently weak for a superfluid phase to theoretically emerge below a critical temperature of around 10 K. Importantly, for realistic experimental parameters interlayer excitons quasi-condense in a state with finite momentum, so that the superfluid is optically inactive and flows spontaneously.

6 pages, 4 figures

References in corpus (11)

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• Moiré excitons: from programmable quantum emitter arrays to spin-orbit coupled artificial lattices
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• High-temperature superfluidity with indirect excitons in van der Waals heterostructures
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• Exciton Condensation and Perfect Coulomb Drag
• Condensation signatures of photogenerated interlayer excitons in a van der Waals heterostack
• Moiré and beyond in transition metal dichalcogenide twisted bilayers
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Cited by in corpus (17)

• Spontaneous coherence in spatially extended photonic systems: Non-Equilibrium Bose-Einstein condensation
• Moiré-Bose-Hubbard model for interlayer excitons in twisted transition metal dichalcogenide heterostructures
• Second harmonic generation control in twisted bilayers of transition metal dichalcogenides
• Spatially indirect intervalley excitons in bilayer WSe2
• Highly Tunable Ground and Excited State Excitonic Dipoles in Multilayer 2H-MoSe${}_2$
• Extended spatial coherence of interlayer excitons in MoSe${}_2$/WSe${}_2$ heterobilayers
• Bosonic Delocalization of Dipolar Moiré Excitons
• Exciton-phonon-scattering: A competition between bosonic and fermionic nature of bound electron-hole pairs
• Leaky exciton condensates in transition metal dichalcogenide moiré bilayers
• Quantum anomalous Hall effect and electric-field-induced topological phase transition in AB-stacked MoTe${}_2$/WSe${}_2$ moiré heterobilayers
• Electrically tunable dipolar interactions between layer-hybridized excitons
• Accurate force-field methodology capturing atomic reconstructions in transition metal dichalcogenide moiré systems
• Confined-state physics and signs of fermionization of moiré excitons in WSe${}_2$/MoSe${}_2$ heterobilayers
• Moiré exciton condensate: nonlinear Dirac point, broken-symmetry Bloch waves and unusual optical selection rules
• Fermionic vs. bosonic thermalization in the phonon-driven exciton dynamics: An analytic dimensionality study
• Laterally Extended States of Interlayer Excitons in Reconstructed MoSe${}_2$/WSe${}_2$ Heterostructures
• Non-local interactions and supersolidity of moiré excitons