Abstract
We propose a method for finding analytical solutions of the
Bogoliubov–de Gennes (BdG) equations for the low-lying collective
excitations in a harmonically trapped Bose-Einstein condensate beyond
the Thomas-Fermi limit. We first use a simple variational wave function
for ground state to eliminate the divergence at the boundary layer of
the condensate, which appears in the Thomas-Fermi approximation. We then
solve the BdG equations analytically and obtain explicit and
divergence-free expressions for the eigenvalues and eigenfunctions of
the excitations for the traps with spherical and cylindrical symmetries.
The solutions of the zero-energy mode of the BdG equations are also
presented.
Original language | English |
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Article number | 063608 |
Journal | Physical Review A |
Volume | 69 |
Issue number | 6 |
DOIs | |
Publication status | Published - 15 Jun 2004 |