English

Strong-coupling perturbation theory for the two-dimensional Bose-Hubbard model in a magnetic field

Strongly Correlated Electrons 2009-10-31 v1

Abstract

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.

Keywords

Cite

@article{arxiv.cond-mat/9812253,
  title  = {Strong-coupling perturbation theory for the two-dimensional Bose-Hubbard model in a magnetic field},
  author = {M. Niemeyer and J. K. Freericks and H. Monien},
  journal= {arXiv preprint arXiv:cond-mat/9812253},
  year   = {2009}
}

Comments

7 pages, 5 figures included