Polariton Condensation in Gap-Confined States of Photonic Crystal Waveguides

F. Riminucci, A. Gianfrate, D. Nigro, V. Ardizzone, S. Dhuey, L. Francaviglia, K. Baldwin, L. N. Pfeiffer, D. Ballarini, D. Trypogeorgos, A. Schwartzberg, D. Gerace, D. Sanvitto

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


The development of patterned multiquantum well heterostructures in GaAs/AlGaAs waveguides has recently made it possible to achieve exciton-polariton condensation in a topologically protected bound state in the continuum (BIC). Polariton condensation was shown to occur above a saddle point of the two-dimensional polariton dispersion in a one-dimensional photonic crystal waveguide. A rigorous analysis of the condensation phenomenon in these systems, as well as the role of the BIC, is still missing. In the present Letter, we theoretically and experimentally fill this gap by showing that polariton confinement resulting from the negative effective mass and the photonic energy gap in the dispersion play a key role in enhancing the relaxation toward the condensed state. In fact, our results show that low-threshold polariton condensation is achieved within the effective trap created by the exciting laser spot, regardless of whether the resulting confined mode is long-lived (polariton BIC) or short-lived (lossy mode). In both cases, the spatial quantization of the polariton condensate and the threshold differences associated to the corresponding state lifetime are measured and characterized. For a given negative mass, a slightly lower condensation threshold from the polariton BIC mode is found and associated to its reduced radiative losses, as compared to the lossy one.

Original languageEnglish (US)
Article number246901
JournalPhysical review letters
Issue number24
StatePublished - Dec 15 2023
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


Dive into the research topics of 'Polariton Condensation in Gap-Confined States of Photonic Crystal Waveguides'. Together they form a unique fingerprint.

Cite this