All Optical Production of Degenerate Fermi gas and Quantum simulation in Optical lattices

Experiments with Ultracold atoms opens the possibility to investigate quantum many-body physics in a controllable environment. Using ultracold atoms in optical lattices can be seen as an implementation of a quantum simulator with exceptional purity and the system can be engineered using tools that are developed in the field of atomic physics over the last few decades. With the high degree of tunability and the possibility of efficient detection techniques, these systems opened the pathway to a wide variety of applications in several fields especially in condensed matter physics.

We aim to study ultracold fermi gas in optical lattices, mainly in disordered optical lattice potentials, and the atomic interactions that lead to localization effect. We have developed an efficient production scheme for a large quantum degenerate sample of fermionic lithium. These atoms are an ideal choice as they can be used to realize a strongly interacting quantum gas with long lifetimes. The approach is based on the narrow-line 2S1/2→3P3/2 laser cooling and the transport and evaporation of the trapped atoms into the quantum degenerate regime using an Optical Dipole Trap.

We have set up a 2D optical lattice using two orthogonal standing waves and an "accordion" type optical lattice to ensure two-dimensionality. The relative phase between lattice beams must be stabilized in time to have well-defined trap depths for holding atoms. We use a Michelson-type interferometer setup based on a Red Pitaya FPGA with PID control for phase stabilization. Similarly, an imaging phase stabilization scheme is implemented for the "accordion" lattice phase stabilization. We extend this setup to a disordered lattice by adding disorder in the form of an optical speckle potential formed by a single blue-detuned laser beam focused through a diffuser and a high-numerical-aperture microscope objective. The accessible ranges of the Hubbard parameters in the Disordered Fermi Hubbard Hamiltonian were theoretically determined with our laser parameters to ensure the possibility of an efficiently tunable system for the future steps.

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