Abstract
We study correlated phases occurring in the flat lowest band of the dice-lattice model at flux density one-half. We discuss how to realize this model, also referred to as the lattice, in cold atomic gases. We construct the projection of the model to the lowest dice band, which yields a Hubbard Hamiltonian with interaction-assisted hopping processes. We solve this model for bosons in two limits. In the limit of large density, we use Gross-Pitaevskii mean-field theory to reveal time-reversal symmetry breaking vortex lattice phases. At low density, we use exact diagonalization to identify three stable phases at fractional filling factors of the lowest band, including a classical crystal at , a supersolid state at , and a Mott insulator at .
- Received 1 November 2011
DOI:https://doi.org/10.1103/PhysRevLett.108.045306
© 2012 American Physical Society