Quantum phases in tunable state-dependent hexagonal optical lattices

24 January 2014

Photo: AG Sengstock

We study the ground-state properties of ultracold bosonic atoms on a state-dependent graphene-like honeycomb lattice. We discuss the various geometries accessible with this lattice setup and present a novel scheme to control the energy offset between the two triangular sublattices A and B 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. Using a cluster mean field method, we compute the phase diagrams and find good agreement with the experimental data for the superfluid to Mott insulator transition.

Phys. Rev. A 90, 013614 (2014)

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