English

Calculation of collective modes for the Bose-Hubbard model with confinement

Other Condensed Matter 2009-11-10 v2

Abstract

The collective excitations in the Bose-Hubbard model in a trap are studied by means of numerical diagonalization in one dimension. The strength function is calculated for monopole and dipole perturbations, and moments of the strength function are utilized in order to obtain information about the collective behavior under external forces. In the superfluid regime, the spectrum is found to be exhausted by one single frequency, while in systems that contain a Mott insulating plateau several frequencies are excited. An explanation of recent experimental findings in terms of a Mott plateau is suggested.

Keywords

Cite

@article{arxiv.cond-mat/0408569,
  title  = {Calculation of collective modes for the Bose-Hubbard model with confinement},
  author = {Emil Lundh},
  journal= {arXiv preprint arXiv:cond-mat/0408569},
  year   = {2009}
}

Comments

4 pages, 5 figures; submitted to PRA. One figure changed