DOI: https://doi.org/10.30970/jps.11.055
STRUCTURE FACTOR OF BOSE-CONDENSED SYSTEMS
V. I. Yukalov
Bogoliubov Laboratory of Theoretical Physics,
Joint
Institute for Nuclear Research, Dubna 141980, Russia
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Journal of Physical Studies 11(1), 55–62 (2007)
DOI: https://doi.org/10.30970/jps.11.055 STRUCTURE FACTOR OF BOSE-CONDENSED SYSTEMSV. I. Yukalov
Bogoliubov Laboratory of Theoretical Physics, |
|
The structure factor for a Bose system with Bose-Einstein condensate is considered in the frame of the self-consistent mean-field approximation. The accomplished analysis demonstrates the principal importance of the following three points: the necessity of preserving the approximation order, the necessity of taking into account anomalous averages, and the necessity of gauge symmetry breaking. If any one of these necessary conditions is not satisfied, calculations yield the appearance of unphysical divergences of the structure factor implying the occurrence of fictitious instability, which contradicts experiments.
PACS number(s): 03.75.Hh, 03.75.Nt, 05.30.Ch, 05.30.Jp, 67.40.Db