Abstract
We determine the extent to which Lifshitz tail states can be defined in a condensed Bose system. This provides a justification for the inert-layer picture in the study of helium on Vycor. We argue that, in three dimensions, hard-core bosons can be trapped by a sufficiently deep potential well despite a strong tendency for all particles to participate in the Bose-Einstein condensate. This is demonstrated by a variant of the conventional spin-boson problem. We find that phase fluctuations in the condensate tend to depress particle exchange between the trap and the rest of the system and hence has an enhancing effect in terms of Lifshitz-tail localization. However at low densities (near onset of condensation) we argue that the condensate will be relatively enhanced compared to the inert layer model, in agreement with experiment.
Original language | English |
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Pages (from-to) | 1729-1742 |
Number of pages | 14 |
Journal | Journal of Physics: Condensed Matter |
Volume | 4 |
Issue number | 7 |
DOIs | |
Publication status | Published - 17 Feb 1992 |