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arXiv · 0710.0522

Localization and delocalization of ultracold bosonic atoms in finite optical lattices

Dirk-Sören Lühmann·Kai Bongs·Klaus Sengstock·Daniela Pfannkuche
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Abstract

We study bosonic atoms in small optical lattices by exact diagonalization and observe a striking similarity to the superfluid to Mott insulator transition in macroscopic systems. The momentum distribution, the formation of an energy gap, and the pair correlation function show only a weak size dependence. For noncommensurate filling we reveal in deep lattices a mixture of localized and delocalized particles, which is sensitive to lattice imperfections. Breaking the lattice symmetry causes a Bose-glass-like behavior. We discuss the nature of excited states and orbital effects by using an exact diagonalization technique that includes higher bands.

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Dirk-Sören Lühmann, Kai Bongs, Klaus Sengstock, Daniela Pfannkuche. 2008-04-14. Localization and delocalization of ultracold bosonic atoms in finite optical lattices. https://doi.org/10.1103/physreva.77.023620

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