1997/05/31 by F. Dalfovo, S. Giorgini, M. Guilleumas +3 · 3 citations
Computer Science · Physics and Astronomy · #Angular momentum #Bose gas #Bose–Einstein condensate #Cold Atom Physics and Bose-Einstein Condensates #Excitation #Excited state #Fock space #Harmonic oscillator #Hartree–Fock method #Particle (ecology) #Physics #Quantum #Quantum Information and Cryptography #Quantum electrodynamics #Quantum mechanics #Quantum, superfluid, helium dynamics #Quasiparticle #Range (aeronautics) #Semiclassical physics #cond-mat
paper · pdf · doi:10.1103/physreva.56.3840
published as Phys. Rev. A, 56 (1997) 3840 · 16 pages, REVTeX, 6 figures; misprints corrected; some clarifying remarks included
arxiv created 1997/07/02 · openalex publication_date 1997/11/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The density of states of a Bose-condensed gas confined in a harmonic trap is investigated. The predictions of Bogoliubov theory are compared with those of Hartree-Fock theory and of the hydrodynamic model. We show that the Hartree-Fock scheme provides an excellent description of the excitation spectrum in a wide range of energy, revealing a major role played by single-particle excitations in these confined systems. The crossover from the hydrodynamic regime, holding at low energies, to the independent-particle regime is explicitly explored by studying the frequency of the surface mode as a function of their angular momentum. The applicability of the semiclassical approximation for the excited states is also discussed. We show that the semiclassical approach provides simple and accurate formulas for the density of states and the quantum depletion of the condensate.