Boundary layers and emitted excitations in nonlinear Schrodinger superflow past a disk

PHYSICA D-NONLINEAR PHENOMENA

卷:210

Article

Pham, CT ; Nore, C ; Brachet, ME

关键词: superfluidity;    critical speed;    boundary layers;    Bose-Einstein condensates;    saddle-node bifurcation;    Gross-Pitaevskii equation;   

DOI  :  10.1016/j.physd.2005.07.013

来源: Elsevier

【 摘 要 】

The stability and dynamics of nonlinear Schrodinger superflows past a two-dimensional disk are investigated using a specially adapted pseudo-spectral method based on mapped Chebychev polynomials. This efficient numerical method allows the imposition of both Dirichlet and Neumann boundary conditions at the disk border. Small coherence length boundary-layer approximations to stationary solutions are obtained analytically. Newton branch-following is used to compute the complete bifurcation diagram of stationary solutions. The dependence of the critical Mach number on the coherence length is characterized. Above the critical Mach number, at coherence length larger than fifteen times the diameter of the disk, rarefaction pulses are dynamically nucleated, replacing the vortices that are nucleated at small coherence length. (c) 2005 Elsevier B.V All rights reserved.

【 授权许可】

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