Háskóli Íslands (HÍ)University of Iceland (UI)Waldherr, MaxLundt, NilsKlaas, MartinBetzold, SimonWurdack, MatthiasBaumann, VasilijEstrecho, EliezerNalitov, AntonCherotchenko, EvgeniaCai, HuiOstrovskaya, Elena A.Kavokin, Alexey V.Tongay, SefaattinKlembt, SebastianHöfling, SvenSchneider, Christian2019-12-042019-12-042018-08-16Waldherr, M., Lundt, N., Klaas, M. et al. Observation of bosonic condensation in a hybrid monolayer MoSe2-GaAs microcavity. Nat Commun 9, 3286 (2018) doi:10.1038/s41467-018-05532-72041-1723https://hdl.handle.net/20.500.11815/1369Publisher's version (útgefin grein)Bosonic condensation belongs to the most intriguing phenomena in physics, and was mostly reserved for experiments with ultra-cold quantum gases. More recently, it became accessible in exciton-based solid-state systems at elevated temperatures. Here, we demonstrate bosonic condensation driven by excitons hosted in an atomically thin layer of MoSe2, strongly coupled to light in a solid-state resonator. The structure is operated in the regime of collective strong coupling between a Tamm-plasmon resonance, GaAs quantum well excitons, and two-dimensional excitons confined in the monolayer crystal. Polariton condensation in a monolayer crystal manifests by a superlinear increase of emission intensity from the hybrid polariton mode, its density-dependent blueshift, and a dramatic collapse of the emission linewidth, a hallmark of temporal coherence. Importantly, we observe a significant spin-polarization in the injected polariton condensate, a fingerprint for spin-valley locking in monolayer excitons. Our results pave the way towards highly nonlinear, coherent valleytronic devices and light sources.eninfo:eu-repo/semantics/openAccessPolaritonsTwo-dimensional materialsEðlisfræðiÖreindirinfo:eu-repo/semantics/articleNature Communications10.1038/s41467-018-05532-7