All-Optical Production of Quantum Degeneracy and Molecular Bose–Einstein Condensation of ⁶Li

We achieve a highly degenerate and strongly interacting Fermi gas in a mixture of the two lowest hyperfine states of ⁶Li by direct evaporative cooling in a high power crossed optical dipole trap. The trap is loaded from a large atom number magneto-optical trap realized by a laser system of 2.5-W intracavity-frequency-doubled light output at 671 nm. With this system, we also demonstrate the production of a molecular Bose–Einstein condensate (mBEC) of ⁶Li₂, and observe the anisotropic expansion of Fermi gases in the so-called BEC–Bardeen–Cooper–Schrieffer crossover regime.