Calculation of collective modes for the Bose-Hubbard model with confinement
2004 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 70, no 6, 061602- p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2004. Vol. 70, no 6, 061602- p.
IdentifiersURN: urn:nbn:se:kth:diva-39730DOI: 10.1103/PhysRevA.70.061602ISI: 000226418900011ScopusID: 2-s2.0-42749106023OAI: oai:DiVA.org:kth-39730DiVA: diva2:444708
QC 201109292011-09-292011-09-122011-09-29Bibliographically approved