dc.contributor.author Chiacchio, EIR dc.contributor.author Nunnenkamp, Andreas dc.date.accessioned 2018-11-20T00:30:20Z dc.date.available 2018-11-20T00:30:20Z dc.date.issued 2018-08-15 dc.identifier.issn 2469-9926 dc.identifier.uri https://www.repository.cam.ac.uk/handle/1810/285435 dc.description.abstract We investigate the physics of a gas of ultracold atoms coupled to three single-mode optical cavities and transversely pumped with a laser. Recent work has demonstrated that, for two cavities, the $\mathbb{Z}_{2}$ symmetries of each cavity can be combined into a global $U(1)$ symmetry. Here, we show that when adding an extra cavity mode, the low-energy description of this system can additionally exhibit an $SO(3)$ rotational symmetry which can be spontaneously broken. This leads to a superradiant phase transition in all the cavities simultaneously, and the appearance of Goldstone and amplitude modes in the excitation spectrum. We determine the phase diagram of the system, which shows the emergence and breaking of the continuous symmetries and displays first- and second-order phase transitions. We also obtain the excitation spectrum for each phase and discuss the atomic self-organized structures that emerge in the different superradiant phases. We argue that coupling the atoms equally to $n$ different modes will in general generate a global $SO(n)$ symmetry if the mode frequencies can be tuned to the same value. dc.publisher American Physical Society (APS) dc.title Emergence of continuous rotational symmetries in ultracold atoms coupled to optical cavities dc.type Article prism.issueIdentifier 2 prism.publicationDate 2018 prism.publicationName Physical Review A prism.volume 98 dc.identifier.doi 10.17863/CAM.32795 dcterms.dateAccepted 2018-07-19 rioxxterms.versionofrecord 10.1103/PhysRevA.98.023617 rioxxterms.licenseref.uri http://www.rioxx.net/licenses/all-rights-reserved rioxxterms.licenseref.startdate 2018-08-15 dc.contributor.orcid Nunnenkamp, Andreas [0000-0003-2390-7636] dc.identifier.eissn 2469-9934 dc.publisher.url http://dx.doi.org/10.1103/PhysRevA.98.023617 rioxxterms.type Journal Article/Review pubs.funder-project-id The Royal Society (uf130303) pubs.funder-project-id Engineering and Physical Sciences Research Council (EP/N509620/1) cam.issuedOnline 2018-08-15 rioxxterms.freetoread.startdate 2019-08-15
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