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

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.

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

References in corpus (7)

• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Transition from a strongly interacting 1D superfluid to a Mott insulator
• Josephson Junction Arrays with Bose-Einstein Condensates
• Excitations of a Superfluid in a 3D Optical Lattice
• Collective Modes of Trapped Fermi Gases in the Normal Phase
• Effects of Inhomogeneity on the Spectrum of the Mott-Insulator State
• Dipole and monopole modes in the Bose-Hubbard model in a trap

Cited by in corpus (8)

• Spectroscopy of ultracold atoms by periodic lattice modulations
• Ultracold atoms confined in an optical lattice plus parabolic potential: a closed-form approach
• Wavepacket dynamics in energy space of a chaotic trimeric Bose-Hubbard system
• Breathing mode in the Bose-Hubbard chain with a harmonic trapping potential
• One-dimensional extended Bose-Hubbard model with a confining potential: a DMRG analysis
• Collective modes of a strongly interacting Bose gas: probing the Mott transition
• Mott insulator dynamics
• Controlled quantum stirring of Bose-Einstein condensates