Search results for "optical lattice"
showing 4 items of 54 documents
Exploring Interacting Topological Insulators with Ultracold Atoms: The Synthetic Creutz-Hubbard Model
2016
25 pags., 13 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0
Experimental demonstration of single-site addressability in a two-dimensional optical lattice
2009
We demonstrate single site addressability in a two-dimensional optical lattice with 600 nm lattice spacing. After loading a Bose-Einstein condensate in the lattice potential we use a focused electron beam to remove atoms from selected sites. The patterned structure is subsequently imaged by means of scanning electron microscopy. This technique allows us to create arbitrary patterns of mesoscopic atomic ensembles. We find that the patterns are remarkably stable against tunneling diffusion. Such micro-engineered quantum gases are a versatile resource for applications in quantum simulation, quantum optics and quantum information processing with neutral atoms.
Flat bands, Dirac cones, and atom dynamics in an optical lattice
2010
We study atoms trapped with a harmonic confinement in an optical lattice characterized by a flat band and Dirac cones. We show that such an optical lattice can be constructed which can be accurately described with the tight binding or Hubbard models. In the case of fermions the release of the harmonic confinement removes fast atoms occupying the Dirac cones while those occupying the flat band remain immobile. Using exact diagonalization and dynamics we demonstrate that a similar strong occupation of the flat band does not happen in bosonic case and furthermore that the mean field model is not capable for describing the dynamics of the boson cloud.
Quantum effects in one-dimensional optical flat-band lattices
2011
I numerically simulated one-dimensional lattice systems describable by the Hubbard-model and containing a flat-band. I studied the manner in which particles initially held in place by a parabolic confinement potential are dispersed across the lattice after the potential is removed. I also studied currents flowing within one-dimensional Hubbard-rings. In both of these cases I observed that the flat dispersion relation of the flat-band manifests itself as the immobility of the particles occupying it. Particles occupying flat-band states do not disperse even after the removal of any external confinement, neither do they contribute to a current within a ring.