Tunneling of a few strongly repulsive hard-sphere bosons in an optical lattice with tight external harmonic confinement: A quantum Monte Carlo investigation in continuous space
arXiv:0905.1147 · doi:10.1103/PhysRevA.81.043603
Abstract
The effect of strongly repulsive interactions on the tunneling amplitude of hard-sphere (HS) bosons confined in a simple cubic (sc) optical lattice plus tight external harmonic confinement in continuous space is investigated. The quantum variational Monte Carlo (VMC) and the variational path integral Monte Carlo (VPI) techniques are used at zero temperature. The effects of the lattice spacing on the tunneling amplitude is also considered. The occupancies of the lattice sites as a function of the repulsion between the bosons are further revealed. Our chief result is, that for a small number of bosons (N=8) the overlap of the wave functions in neighboring wells does not change with an increase of the repulsive interactions and changes only minimally for a larger number of particles (N=40). The tunneling amplitude rises with a reduction in the lattice spacing. In addition, the occupancy of the center of the trap decreases in favor of a rise in the occupancy of the lattice sites at the edges of the trap with increasing HS repulsion. Further, it was found that the energy per particle at certain optical depths is insensitive to the number of particles and variations in the HS diameter of the bosons. In order to support our results, we compare the VMC results with corresponding VPI results.
16 pages, 24 figures. This is an improvement of the previous version in which we consider the presence of pair-tunneling in the strongly interacting regime. The tunneling amplitude is measured in terms of the overlap of wave functions in neighboring wells
References in corpus (24)
- Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
- Direct Observation of Second Order Atom Tunnelling
- Interference pattern and visibility of a Mott insulator
- Few-boson dynamics in double wells: From single-atom to correlated-pair tunneling
- Supersolid Bose-Fermi Mixtures in Optical Lattices
- Matter-wave solitons in radially periodic potentials
- Quantum Monte Carlo study of confined fermions in one-dimensional optical lattices
- Tunneling dynamics of few bosons in a double well
- Superfluid to Mott-insulator transition in Bose-Hubbard models
- Single-particle versus pair condensation of hard-core bosons with correlated hopping
- Coherent matter waves emerging from Mott-insulators
- Atom-Pair Tunneling and Quantum Phase Transition in Strong Interaction Regime
- Signatures of the superfluid to Mott-insulator transition in the excitation spectrum of ultracold atoms
- On-site number statistics of ultracold lattice bosons
- Simulations of ultracold bosonic atoms in optical lattices with anharmonic traps
- Bose-Einstein condensation in an optical lattice
- Supersolids in one dimensional Bose Fermi mixtures
- Characteristics of Bose-Einstein condensation in an optical lattice
- Path integral formulation of the tunneling dynamics of a superfluid Fermi gas in an optical potential
- Localization and delocalization of ultracold bosonic atoms in finite optical lattices
- Coexistence of superfluid and Mott phases of lattice bosons
- Condensate depletion in two-species Bose gases: A variational Quantum Monte Carlo study
- Phases of Bosons or Fermions in confined optical lattices
- From the superfluid to the Mott regime and back: triggering a non-trivial dynamics in an array of coupled condensates