title: Spatial Coherence and Stability in a Disordered Organic Polariton Condensate.
abstract: Although only a handful of organic materials have shown polariton condensation, their study is rapidly becoming more accessible. The spontaneous appearance of long-range spatial coherence is often recognized as a defining feature of such condensates. In this Letter, we study the emergence of spatial coherence in an organic microcavity and demonstrate a number of unique features stemming from the peculiarities of this material set. Despite its disordered nature, we find that correlations extend over the entire spot size, and we measure g(1)(r,r') values of nearly unity at short distances and of 50% for points separated by nearly 10  μm . We show that for large spots, strong shot-to-shot fluctuations emerge as varying phase gradients and defects, including the spontaneous formation of vortices. These are consistent with the presence of modulation instabilities. Furthermore, we find that measurements with flat-top spots are significantly influenced by disorder and can, in some cases, lead to the formation of mutually incoherent localized condensates.
authors.affiliation: Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: K S
authors.initials: KS
authors.lastname: Daskalakis
authors.affiliation: Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: S A
authors.initials: SA
authors.lastname: Maier
authors.affiliation: Department of Engineering Physics, École Polytechnique de Montréal, Montréal, Québec H3C 3A7, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Kéna-Cohen
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D055590:Electromagnetic Phenomena; D007368:Interferometry; D007834:Lasers; D008962:Models, Theoretical; D055095:Optics and Photonics; D017785:Photons; D013691:Tellurium / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D013691:Tellurium; C028337:cadmium telluride