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arXiv · 0705.0943

Localization by entanglement

Joachim Brand·Sergej Flach·Victor Fleurov·L. S. Schulmann·Denis Tolkunov
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Abstract

We study the localization of bosonic atoms in an optical lattice, which interact in a spatially confined region. The classical theory predicts that there is no localization below a threshold value for the strength of interaction that is inversely proportional to the number of participating atoms. In a full quantum treatment, however, we find that localized states exist for arbitrarily weak attractive or repulsive interactions for any number ($>1$) of atoms. We further show, using an explicit solution of the two-particle bound state and an appropriate measure of entanglement, that the entanglement tends to a finite value in the limit of weak interactions. Coupled with the non-existence of localization in an optimized quantum product state, we conclude that the localization exists by virtue of entanglement.

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Joachim Brand, Sergej Flach, Victor Fleurov, L. S. Schulmann, Denis Tolkunov. 2008-08-05. Localization by entanglement. https://doi.org/10.1209/0295-5075/83/40002

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