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The most recent advances in ultra-cold gases experiments allow reproducing in the
laboratory several versions of the Hubbard Hamiltonian describing particles on a lattice.
This is a particular Hamiltonian of great interest in condensed matter physics which is
good to describe various kinds of strongly correlated systems.
We study samples of ultra-cold dipolar atoms in 2D optical lattices, which possess an
extremely rich physics thanks to the large number of tunable parameters: tunneling rate,
tunable through the lattice strength, dipole-dipole interaction and on-site interaction,
both tunable through lattice strength and especially through the orientation angle of the
dipoles. Our investigation focuses for the first time on the metastable states of the system. The existence of many nearly degenerate stationary states makes the system similar to a disordered one and opens possibilities of applications in quantum information processing as quantum memories. Performing a classical calculation for any given orientation of the dipoles indeed we find up to few hundreds metastable states of a 4by4 square lattice, half filled with dipolar Bosons. At the moment we are implementing a mean-field Gutzwiller Ansatz (GA) to extend the previous analysis to the quantum regime and to finite temperature, and to allow the investigation of the dynamics. |
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