2014/05/20 by Peter V. Pikhitsa, Pikhitsa, Peter V.
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Quantum Gases (cond-mat.quant-gas) #Quantum, superfluid, helium dynamics #cond-mat.quant-gas
paper · pdf · doi:10.48550/arxiv.1405.5035
6 pages, 2 figures
arxiv created 2014/05/20 · openalex publication_date 2014/05/20 · arxiv updated 2014/05/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider a Bose-Einstein condensate of bosons with repulsion, described by the Gross-Pitaevskii equation and restricted by an impenetrable "hard wall" (either rigid or flexible) which is intended to suppress the "snake instability" inherent for dark solitons. We solve analytically the Bogoliubov - de Gennes equations to find the spectra of gapless Bogoliubov excitations localized near the "domain wall" and therefore split from the bulk excitation spectrum of the Bose-Einstein condensate. The "domain wall" may model either the surface of liquid helium or of a strongly trapped Bose-Einstein condensate. The dispersion relations for the surface excitations are found for all wavenumbers k along the surface up to the "free-particle" behavior k → ∞, the latter was shown to be bound to the "hard wall" with some "universal" energy Δ.