Condensation of Exciton-Polaritons in a Bound State in the Continuum: Effects of the Excitation Spot Size and Polariton Transport.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39520678.
- Also identified by DOI 10.1021/acsnano.4c09970 and PMC identifier 11580381.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
We report the formation of polariton condensates from strongly coupled molecules to bound states in the continuum with quadrupolar character in a metasurface of silicon nanoparticles. Our experiments demonstrate a strong dependence of the condensation threshold on the excitation spot size. The condensation threshold decreases as the excitation spot size increases, achieving thresholds below 3 μm cm<sup>-2</sup> for spot sizes of around 1 mm<sup>2</sup> and condensate lifetimes exceeding 20 ps. The strong dependence of the condensation threshold on the spot size is caused by the long propagation length of the polaritons. We reproduce this dependence in simulations by including a term for the ballistic transport of exciton-polaritons in the rate equations describing the condensation. These results illustrate the critical role that polariton transport plays in condensation and highlight the relevance of considering the size of the excitation in condensation experiments.