Localization by entanglement

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.

6 pages, 4 figures; final published version with small changes in response to reviewer comments

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Cited by in corpus (3)

• Quantum-entanglement aspects of polaron systems
• On dynamical stability of composite quantum particles: when entanglement is enough and when interaction is needed
• Few-body bound states of bosonic mixtures in two-dimensional optical lattices