Superfluid Flow Past an Obstacle in Annular Boseâ•fiEinstein Condensates
نویسندگان
چکیده
We investigate the flow of a one-dimensional nonlinear Schrödinger model with periodic boundary conditions past an obstacle, motivated by recent experiments with Bose–Einstein condensates in ring traps. Above certain rotation velocities, localized solutions with a nontrivial phase profile appear. In striking difference from the infinite domain, in this case there are many critical velocities. At each critical velocity, the steady flow solutions disappear in a saddle-center bifurcation. These interconnected branches of the bifurcation diagram lead to additions of circulation quanta to the phase of the associated solution. This, in turn, relates to the manifestation of persistent current in numerous recent experimental and theoretical works, the connections to which we touch upon. The complex dynamics of the identified waveforms and the instability of unstable solution branches are demonstrated in 1D simulations. Proofof-principle 2D simulations corroborating the emergence of persistent current in the latter setting are also performed. PACS numbers: 03.75.Kk, 67.85.-d, 37.10.Vz, 47.37.+q ar X iv :1 51 2. 07 92 4v 1 [ co nd -m at .q ua nt -g as ] 2 4 D ec 2 01 5 Superfluid flow past an obstacle in annular Bose–Einstein condensates 2
منابع مشابه
Formation of Bright Matter-Wave Solitons during the Collapse of Boseâ•fiEinstein Condensates
متن کامل
Spectral Stability of Vortices in Two-Dimensional Boseâ•fiEinstein Condensates via the Evans Function and Krein Signature
We investigate spectral stability of vortex solutions of the Gross-Pitaevskii equation, a mean-field approximation for Bose-Einstein condensates (BEC) in an effectively two-dimensional axisymmetric harmonic trap. We study eigenvalues of the linearization both rigorously and through computation of the Evans function, a sensitive and robust technique whose use we justify mathematically. Computati...
متن کاملTwo-dimensional supersonic nonlinear Schrödinger flow past an extended obstacle.
Supersonic flow of a superfluid past a slender impenetrable macroscopic obstacle is studied in the framework of the two-dimensional (2D) defocusing nonlinear Schrödinger (NLS) equation. This problem is of fundamental importance as a dispersive analog of the corresponding classical gas-dynamics problem. Assuming the oncoming flow speed is sufficiently high, we asymptotically reduce the original ...
متن کاملBreakdown of superfluidity of an atom laser past an obstacle
The 1D flow of a continuous beam of Bose-Einstein condensed atoms in the presence of an obstacle is studied as a function of the beam velocity and of the type of perturbing potential (representing the interaction of the obstacle with the atoms of the beam). We identify the relevant regimes: stationary/time-dependent and superfluid/dissipative; the absence of drag is used as a criterion for supe...
متن کاملCoupled counterrotating polariton condensates in optically defined annular potentials.
Polariton condensates are macroscopic quantum states formed by half-matter half-light quasiparticles, thus connecting the phenomena of atomic Bose-Einstein condensation, superfluidity, and photon lasing. Here we report the spontaneous formation of such condensates in programmable potential landscapes generated by two concentric circles of light. The imposed geometry supports the emergence of an...
متن کامل