Quantum phases in tunable state-dependent hexagonal optical lattices
Abstract
We study the ground-state properties of ultracold bosonic atoms in a state-dependent graphene-like honeycomb optical lattice, where the degeneracy between the two triangular sublattices A and B can be lifted. We discuss the various geometries accessible with this lattice setup and present a novel scheme to control the energy offset with external magnetic fields. The competition of the on-site interaction with the offset energy leads to Mott phases characterized by population imbalances between the sublattices. For the definition of an optimal Hubbard model, we demonstrate a scheme that allows for the efficient computation of Wannier functions. Using a cluster mean-field method, we compute the phase diagrams and provide a universal representation for arbitrary energy offsets. We find good agreement with the experimental data for the superfluid to Mott insulator transition.
Cite
@article{arxiv.1401.5961,
title = {Quantum phases in tunable state-dependent hexagonal optical lattices},
author = {Dirk-Sören Lühmann and Ole Jürgensen and Malte Weinberg and Juliette Simonet and Parvis Soltan-Panahi and Klaus Sengstock},
journal= {arXiv preprint arXiv:1401.5961},
year = {2014}
}