arXiv:cond-mat/0203082 · Physical Review Letters
Mott Domains of Bosons Confined on Optical Lattices
G. G. Batrouni, V. G. Rousseau, Richard T. Scalettar, Marcos Rigol, A. Muramatsu, P. J. H. Denteneer, Matthias Troyer
Abstract
In the absence of a confining potential, the boson-Hubbard model exhibits a superfluid to Mott insulator quantum phase transition at commensurate fillings and strong coupling. We use quantum Monte Carlo simulations to study the ground state of the one-dimensional bosonic Hubbard model in a trap. Some, but not all, aspects of the Mott insulating phase persist. Mott behavior occurs for a continuous range of incommensurate fillings, very different from the unconfined case, and the establishment of the Mott phase does not proceed via a traditional quantum phase transition. These results have important implications for interpreting experiments on ultracold atoms on optical lattices.