Density Modulations Associated with the Dynamical Instability in the Bose-Hubbard Model
arXiv:1410.7869 · doi:10.7566/JPSJ.83.124001
Abstract
A superfluid flow beyond a critical momentum in an optical lattice decays drastically by the interplay between nonlinearity due to the interparticle interactions in Bose-Einstein condensate and periodicity of the lattice; this instability is called dynamical instability. The complex density modulational profiles after the condensate becomes unstable observed experimentally is not completely understood, while the dynamical instability has been studied theoretically and experimentally. In this paper, we analyze the density modulation of condensates as a precursor of the dynamical instability in the two-dimensional Bose-Hubbard model. Our analysis has clarified the unexplored properties of the density modulations associated with the dynamical instability at low filling and in a wide range of interactions, while the previous works have analyzed the density modulation on the basis of Gross-Pitaevskii equation under the specific condition that one-dimensional optical lattice is very shallow and the filling is very large. The numerical simulations based on the dynamical Gutzwiller approximation elucidate that the principal mode of density modulation highly depends on interaction strength U and the momentum acceleration rate. We briefly discuss these features with the stability phase diagram calculated on the basis of the Bogoliubov theory.
5 pages, 4 Postscript figures, uses jpsj3.cls and jpsj-suppl.cls
References in corpus (25)
- Probing the Superfluid to Mott Insulator Transition at the Single Atom Level
- Bright gap solitons of atoms with repulsive interaction
- Bloch oscillations and mean-field effects of Bose-Einstein condensates in 1-D optical lattices
- Landau and Dynamical Instabilities of the Superflow of Bose-Einstein Condensates in Optical Lattices
- Superfluid and Dissipative Dynamics of a Bose-Einstein Condensate in a Periodic Optical Potential
- Dynamical Superfluid-Insulator Transition in a Chain of Weakly Coupled Bose-Einstein Condensates
- Observation of dynamical instability for a Bose-Einstein condensate in a moving 1D optical lattice
- Superfluidity of Bose-Einstein Condensate in An Optical Lattice: Landau-Zener Tunneling and Dynamical Instability
- Oscillating Superfluidity of Bosons in Optical Lattices
- Strongly inhibited transport of a 1D Bose gas in a lattice
- Experimental properties of Bose-Einstein condensates in 1D optical lattices: Bloch oscillations, Landau-Zener tunneling and mean-field effects
- Superfluid current disruption in a chain of weakly coupled Bose-Einstein Condensates
- Phase diagram for a Bose-Einstein condensate moving in an optical lattice
- Unstable regimes for a Bose-Einstein condensate in an optical lattice
- Decay of a superfluid currents in a moving system of strongly interacting bosons
- Superfluid-insulator transition in a moving system of interacting bosons
- Phase-slip induced dissipation in an atomic Bose-Hubbard system
- Role of transverse excitations in the instability of Bose-Einstein condensates moving in optical lattices
- Instabilities of a Bose-Einstein condensate in a periodic potential: an experimental investigation
- Stability of Bose-Einstein condensates in a Kronig-Penney potential
- Dynamical instabilities of Bose-Einstein condensates at the band-edge in one-dimensional optical lattices
- Heavily Damped Motion of One-Dimensional Bose Gases in an Optical Lattice
- Dipole oscillations of confined lattice bosons in one dimension
- Loss and revival of phase coherence in a Bose-Einstein condensate moving through an optical lattice
- Instabilities of Bosonic Spin Currents in Optical Lattices