2015/05/08 by Xue-Feng Zhang, Tao Wang, Sebastian Eggert +1 · 1 citation
Physics and Astronomy · #cond-mat.quant-gas #cond-mat.str-el #physics.atom-ph
paper · pdf · doi:10.1103/physrevb.92.014512
published as Phys. Rev. B. 92, 014512 (2015) · 5 pages with 5 figures. For more information and the latest version see http://www.physik.uni-kl.de/eggert/papers/index.html
arxiv created 2015/05/08 · arxiv updated 2015/07/29
We study the phase diagram of the Bose-Hubbard model on the kagome lattice with a broken sublattice symmetry. Such a superlattice structure can naturally be created and tuned by changing the potential offset of one sublattice in the optical generation of the frustrated lattice. The superstructure gives rise to a rich quantum phase diagram, which is analyzed by combining Quantum Monte Carlo simulations with the Generalized Effective Potential Landau Theory. Mott phases with non-integer filling and a characteristic order along stripes are found, which show a transition to a superfluid phase with an anisotropic superfluid density. Surprisingly, the direction of the superfluid anisotropy is changing between different symmetry directions as a function of the particle number or the hopping strength. Finally, we discuss characteristic signatures of anisotropic phases in time-of-flight absorption measurements.