Nonequilibrium Phase Transition in a Two-Dimensional Driven Open Quantum System
Anno: 2015
Autori: Dagvadorj G., Fellows JM., Matyjaskiewicz S., Marchetti FM., Carusotto I., Szymanska MH.
Affiliazione autori: Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England; Nomura Int Plc, Dept Risk Methodol, London EC4R 3AB, England; Univ Autonoma Madrid, Dept Fis Teor Mat Condensada, E-28049 Madrid, Spain; Univ Autonoma Madrid, Condensed Matter Phys Ctr IFIMAC, E-28049 Madrid, Spain; Univ Trento, INO CNR BEC Ctr, I-38123 Povo, Italy;Univ Trento, Dipartimento Fis, I-38123 Povo, Italy; UCL, Dept Phys & Astron, London WC1E 6BT, England
Abstract: The Berezinskii-Kosterlitz-Thouless mechanism, in which a phase transition is mediated by the proliferation of topological defects, governs the critical behavior of a wide range of equilibrium two-dimensional systems with a continuous symmetry, ranging from spin systems to superconducting thin films and two-dimensional Bose fluids, such as liquid helium and ultracold atoms. We show here that this phenomenon is not restricted to thermal equilibrium, rather it survives more generally in a dissipative highly nonequilibrium system driven into a steady state. By considering a quantum fluid of polaritons of an experimentally relevant size, in the so-called optical parametric oscillator regime, we demonstrate that it indeed undergoes a phase transition associated with a vortex binding-unbinding mechanism. Yet, the exponent of the power-law decay of the first-order correlation function in the (algebraically) ordered phase can exceed the equilibrium upper limit: this shows that the ordered phase of driven-dissipative systems can sustain a higher level of collective excitations before the order is destroyed by topological defects. Our work suggests that the macroscopic coherence phenomena, observed recently in interacting two-dimensional light-matter systems, result from a nonequilibrium phase transition of the Berezinskii-Kosterlitz-Thouless rather than the Bose-Einstein condensation type.
Giornale/Rivista: PHYSICAL REVIEW X
Volume: 5 (4) Da Pagina: 041828-1 A: 041828-9
Parole chiavi: BOSE-EINSTEIN CONDENSATION; SEMICONDUCTOR MICROCAVITIES; SUPERFLUID TRANSITION; EXCITON-POLARITONS; FILMS; GAS
DOI: 10.1103/PhysRevX.5.041028Citazioni: 78dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2024-04-21Riferimenti tratti da Isi Web of Knowledge: (solo abbonati) Link per visualizzare la scheda su IsiWeb: Clicca quiLink per visualizzare la citazioni su IsiWeb: Clicca qui