%0 Journal Article
%T Strong-coupling perturbation theory for the two-dimensional Bose-Hubbard model in a magnetic field
%A M. Niemeyer
%A J. K. Freericks
%A H. Monien
%J Physics
%D 1998
%I arXiv
%R 10.1103/PhysRevB.60.2357
%X The Bose-Hubbard model in an external magnetic field is investigated with strong-coupling perturbation theory. The lowest-order secular equation leads to the problem of a charged particle moving on a lattice in the presence of a magnetic field, which was first treated by Hofstadter. We present phase diagrams for the two-dimensional square and triangular lattices, showing a change in shape of the phase lobes away from the well-known power-law behavior in zero magnetic field. Some qualitative agreement with experimental work on Josephson-junction arrays is found for the insulating phase behavior at small fields.
%U http://arxiv.org/abs/cond-mat/9812253v1