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arXiv · 0908.2026

Interacting trapped bosons yield fragmented condensate states in low dimensions

Uwe R. Fischer·Philipp Bader
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Abstract

We investigate the level population statistics and degree of coherence encoded in the single-particle density matrix of harmonically trapped low-dimensional [quasi-one-dimensional (quasi-1D) or quasi-two-dimensional (quasi-2D)] Bose gases with repulsive contact interactions. Using a variational analysis, we derive fragmentation of the condensate in the weakly confining directions into two (quasi-1D) respectively three (quasi-2D) mutually incoherent macroscopic pieces, upon increasing a dimensionless interaction measure beyond a critical value. Fragmented condensate many-body states in low-dimensional systems therefore occur well before the thermodynamic limit of infinite extension is reached, in which phase fluctuations of the matter wave field create an infinite number of nonmacroscopic fragments.

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Uwe R. Fischer, Philipp Bader. 2010-07-21. Interacting trapped bosons yield fragmented condensate states in low dimensions. https://doi.org/10.1103/physreva.82.013607

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