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arXiv · 1401.5961

Quantum phases in tunable state-dependent hexagonal optical lattices

Dirk-Sören Lühmann·Ole Jürgensen·Malte Weinberg·Juliette Simonet·Parvis Soltan-Panahi·Klaus Sengstock
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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.

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Dirk-Sören Lühmann, Ole Jürgensen, Malte Weinberg, Juliette Simonet, Parvis Soltan-Panahi, Klaus Sengstock. 2014-10-22. Quantum phases in tunable state-dependent hexagonal optical lattices. https://doi.org/10.1103/physreva.90.013614

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