Spin-1 Atoms in Optical Superlattices: Single-Atom Tunneling and Entanglement

Abstract

We examine spinor Bose-Einstein condensates in optical superlattices theoretically using a Bose-Hubbard Hamiltonian that takes spin effects into account. Assuming that a small number of spin-1 bosons is loaded in an optical potential, we study single-particle tunneling that occurs when one lattice site is ramped up relative to a neighboring site. Spin-dependent effects modify the tunneling events in a qualitative and quantitative way. Depending on the asymmetry of the double well different types of magnetic order occur, making the system of spin-1 bosons in an optical superlattice a model for mesoscopic magnetism. We use a double-well potential as a unit cell for a one-dimensional superlattice. Homogeneous and inhomogeneous magnetic fields are applied and the effects of the linear and the quadratic Zeeman shifts are examined. We also investigate the bipartite entanglement between the sites and construct states of maximal entanglement. The entanglement in our system is due to both orbital and spin degrees of freedom. We calculate the contribution of orbital and spin entanglement and show that the sum of these two terms gives a lower bound for the total entanglement.

14 pages, 17 figures

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Cited by in corpus (12)

• Loop Structure Stability of a Double-Well-Lattice BEC
• Mean-Field Analysis of Spinor Bosons in Optical Superlattices
• Analytical approach to the two-site Bose-Hubbard model: from Fock states to Schrödinger cat states and entanglement entropy
• Percolation analysis of a disordered spinor Bose gas
• Entanglement enhancement in spatially inhomogeneous many-body systems
• Magnetic phase diagram and quantum phase transitions in a two-species boson model
• Ground-state entanglement of spin-1 bosons undergoing superexchange interactions in optical superlattices
• Efficient generation of many-body singlet states of spin-1 bosons in optical superlattices
• Spin-driven spatial symmetry breaking of spinor condensates in a double-well
• Ground-states of spin-1 bosons in asymmetric double-wells
• Effective orbital ordering in multiwell optical lattices with fermionic atoms
• Asymmetric sequential Landau-Zener dynamics of Bose condensed atoms in a cavity