title: Bistability in a Driven-Dissipative Superfluid.
abstract: We experimentally study a driven-dissipative Josephson junction array, realized with a weakly interacting Bose-Einstein condensate residing in a one-dimensional optical lattice. Engineered losses on one site act as a local dissipative process, while tunneling from the neighboring sites constitutes the driving force. We characterize the emerging steady states of this atomtronic device. With increasing dissipation strength γ the system crosses from a superfluid state, characterized by a coherent Josephson current into the lossy site, to a resistive state, characterized by an incoherent hopping transport. For intermediate values of γ, the system exhibits bistability, where a superfluid and an incoherent branch coexist. We also study the relaxation dynamics towards the steady state, where we find a critical slowing down, indicating the presence of a nonequilibrium phase transition.
authors.affiliation: Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.|Graduate School Materials Science in Mainz, Staudinger Weg 9, 55128 Mainz, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Labouvie
authors.affiliation: Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: Bodhaditya
authors.initials: B
authors.lastname: Santra
authors.affiliation: Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Heun
authors.affiliation: Department of Physics and Research Center OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: Herwig
authors.initials: H
authors.lastname: Ott