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

Journal Article · Thu Apr 15 00:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.043603· OSTI ID:21408668

Sakhel, Asaad R ^[1]; Dubois, Jonathan L ^[2]; Sakhel, Roger R ^[3]

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1. Al-Balqa Applied University, Faculty of Engineering Technology, Basic Sciences Department, Amman 11134 (Jordan)
2. Lawrence Livermore National Laboratory, 7000 East Ave, L-415, Livermore California 94550 (United States)
3. Department of Basic Sciences, Faculty of Science and Information Technology, Al-Isra University, Amman 11622 (Jordan)

The effect of strongly repulsive interactions on the tunneling amplitude of hard-sphere (HS) bosons confined in a simple cubic optical lattice plus tight external harmonic confinement in continuous space is investigated. The quantum variational Monte Carlo (VMC) and the variational path integral (VPI) Monte Carlo techniques are used at zero temperature. The effects of the lattice spacing on the tunneling amplitude are 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 practically 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-lattice barrier heights 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.

• OSTI ID: 21408668
• Journal Information: Physical Review. A, Vol. 81, Issue 4; Other Information: DOI: 10.1103/PhysRevA.81.043603; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
AMPLITUDES
BOSONS
COMPARATIVE EVALUATIONS
CONFINEMENT
INTERACTIONS
MONTE CARLO METHOD
PARTICLES
PATH INTEGRALS
SPACE
TRAPS
TUNNEL EFFECT
VARIATIONAL METHODS
WAVE FUNCTIONS
CALCULATION METHODS
EVALUATION
FUNCTIONS
INTEGRALS