Microscopic modelling of exciton-polariton diffusion coefficients in atomically thin semiconductors

Abstract

In the strong light-matter coupling regime realized e.g. by integrating semiconductors into optical microcavities, polaritons as new hybrid light-matter quasi-particles are formed. The corresponding change in the dispersion relation has a large impact on optics, dynamics and transport behaviour of semiconductors. In this work, we investigate the strong-coupling regime in hBN-encapsulated MoSe${}_2$ monolayers focusing on exciton-polariton diffusion. Applying a microscopic approach based on the exciton density matrix formalism combined with the Hopfield approach, we predict a drastic increase of the diffusion coefficients by two to three orders of magnitude in the strong coupling regime. We explain this behaviour by the much larger polariton group velocity and suppressed polariton-phonon scattering channels with respect to the case of bare excitons. Our study contributes to a better microscopic understanding of polariton diffusion in atomically thin semiconductors.

10 pages, 4 figures

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Cited by in corpus (9)

• Ultrafast imaging of polariton propagation and interactions
• Exciton optics, dynamics and transport in atomically thin semiconductors
• Twist Angle Tuning of Moiré Exciton Polaritons in van der Waals Heterostructures
• Circumventing the polariton bottleneck via dark excitons in 2D semiconductors
• Signatures of dark excitons in exciton-polariton optics of transition metal dichalcogenides
• Microscopic Theory of Polaron-Polariton Dispersion and Propagation
• Two dimensional semiconductors: optical and electronic properties
• Polariton transport in 2D semiconductors: Phonon-mediated transitions between ballistic, superdiffusive and exciton-limited regimes
• Engineering strong coupling in ultra-compact photonic crystal/2D material platforms