We present a quantum theory of low-lying excitations in a trapped Bose condensate with finite particle numbers. We find that even at zero temperature condensate number fluctuations and/or fluctuations of the excitation frequency due to quantum uncertainties of the mode occupation lead to a collapse of the collective modes due to dephasing. Coherent revivals of the collective excitations are predicted on a much longer time scale. Depletion of collective modes due to second-harmonic generation is discussed.
|Original language||English (US)|
|Number of pages||8|
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|State||Published - 1998|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics