{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:00:19Z","timestamp":1760241619377,"version":"build-2065373602"},"reference-count":19,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2018,6,1]],"date-time":"2018-06-01T00:00:00Z","timestamp":1527811200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>We present the study of the dynamics of a two-ring waveguide structure with space-dependent coupling, linear gain and nonlinear absorption; the system that can be implemented in polariton condensates, optical waveguides and nanocavities. We show that by turning on and off local coupling between rings, one can selectively generate a permanent vortex in one of the rings. We find that due to the modulation instability, it is also possible to observe several complex nonlinear phenomena, including spontaneous symmetry breaking, stable inhomogeneous states with an interesting structure of currents flowing between rings, the generation of stable symmetric and asymmetric circular flows with various vorticities, etc. The latter can be created in pairs (for relatively narrow coupling length) or as a single vortex in one of the channels, which later alternates between channels.<\/jats:p>","DOI":"10.3390\/sym10060195","type":"journal-article","created":{"date-parts":[[2018,6,1]],"date-time":"2018-06-01T03:02:50Z","timestamp":1527822170000},"page":"195","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Vortex Creation without Stirring in Coupled Ring Resonators with Gain and Loss"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2506-5794","authenticated-orcid":false,"given":"Aleksandr","family":"Ramaniuk","sequence":"first","affiliation":[{"name":"Faculty of Physics, University of Warsaw, ul. Pasteura 5, PL-02-093 Warszawa, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nguyen Viet","family":"Hung","sequence":"additional","affiliation":[{"name":"Advanced Institute for Science and Technology, Hanoi University of Science and Technology, 100803 Hanoi, Vietnam"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"Giersig","sequence":"additional","affiliation":[{"name":"Department of Physics, Freie Universit\u00e4t Berlin, Arnimalle 14, D-14195 Berlin, Germany"},{"name":"International Academy of Optoelectronics at Zhaoqing, South China Normal University, 526238 Guangdong, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Krzysztof","family":"Kempa","sequence":"additional","affiliation":[{"name":"Department of Physics, Boston College, Chestnut Hill, MA 02467, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1398-3910","authenticated-orcid":false,"given":"Vladimir V.","family":"Konotop","sequence":"additional","affiliation":[{"name":"Centro de F\u00edsica Te\u00f3rica e Computacional and Departamento de F\u00edsica, Faculdade de Ci\u00eancias, Universidade de Lisboa, Campo Grande, Edif\u00edcio C8, 1749-016 Lisboa, Portugal"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marek","family":"Trippenbach","sequence":"additional","affiliation":[{"name":"Faculty of Physics, University of Warsaw, ul. 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