Controlling coherence via tuning of the population imbalance in a bipartite optical lattice
arXiv:1412.4040 · doi:10.1038/ncomms6735
Abstract
The control of transport properties is a key tool at the basis of many technologically relevant effects in condensed matter. The clean and precisely controlled environment of ultracold atoms in optical lattices allows one to prepare simplified but instructive models, which can help to better understand the underlying physical mechanisms. Here we show that by tuning a structural deformation of the unit cell in a bipartite optical lattice, one can induce a phase transition from a superfluid into various Mott insulating phases forming a shell structure in the superimposed harmonic trap. The Mott shells are identified via characteristic features in the visibility of Bragg maxima in momentum spectra. The experimental findings are explained by Gutzwiller mean-field and quantum Monte Carlo calculations. Our system bears similarities with the loss of coherence in cuprate superconductors, known to be associated with the doping induced buckling of the oxygen octahedra surrounding the copper sites.
6+10 pages, 16 figures
References in corpus (9)
- Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond
- The ALPS project release 1.3: open source software for strongly correlated systems
- Orbital superfluidity in the -band of a bipartite optical square lattice
- Monte Carlo study of two-dimensional Bose-Hubbard model
- Interference pattern and visibility of a Mott insulator
- Expansion of a quantum gas released from an optical lattice
- Bose-Hubbard phase diagram with arbitrary integer filling
- Phases of a 2D Bose Gas in an Optical Lattice
- Perturbative corrections to the Gutzwiller mean-field solution of the Mott-Hubbard model