Self-trapping of exciton-polariton condensates

TL;DR

This paper demonstrates the self-trapping of exciton-polariton condensates due to a polaron-like state formed by local temperature variations, leading to a localized condensate with quantum-limited variances, without requiring defects or resonant driving.

Contribution

It introduces a novel self-trapped exciton-polariton condensate state stabilized by phonon-assisted scattering, expanding understanding of polariton interactions and localization mechanisms.

Findings

Condensate collapses into a bright spot above lasing threshold

Position and momentum variances approach the Heisenberg limit

Self-trapping occurs without defects or resonant driving

Abstract

The self-trapping of exciton-polariton condensates is demonstrated and explained by the formation of a new polaron-like state. Above the polariton lasing threshold, local variation of the lattice temperature provides the mechanism for an attractive interaction between polaritons. Due to this attraction, the condensate collapses into a small bright spot. Its position and momentum variances approach the Heisenberg quantum limit. The self-trapping does not require either a resonant driving force or a presence of defects. The trapped state is stabilized by the phonon-assisted stimulated scattering of excitons into the polariton condensate. While the formation mechanism of the observed self-trapped state is similar to the Landau-Pekar polaron model, this state is populated by several thousands of quasiparticles, in a strike contrast to the conventional single-particle polaron state.