Quantum dynamics of repulsively bound atom pairs in the Bose-Hubbard model
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100080, China
Corresponding author: a email@example.com
Published online: 18 April 2008
We investigate the quantum dynamics of repulsively bound atom pairs in an optical lattice described by the periodic Bose-Hubbard model both analytically and numerically. In the strongly repulsive limit, we analytically study the dynamical problem by the perturbation method with the hopping terms treated as a perturbation. For a finite-size system, we numerically solve the dynamic problem in the whole regime of interaction by the exact diagonalization method. Our results show that the initially prepared atom pairs are dynamically stable and the dissociation of atom pairs is greatly suppressed when the strength of the on-site interaction is much greater than the tunneling amplitude, i.e., the strongly repulsive interaction induces a self-localization phenomenon of the atom pairs.
PACS: 03.75.Kk – Dynamic properties of condensates; collective and hydrodynamic excitations, superfluid flow / 03.75.Lm – Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations / 32.80.Pj – Optical cooling of atoms; trapping
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008