New Facility to Probe Physics With Degenerate Bose and Fermi Gas

A new facility to produce dual species degenerate Bose and Fermi gas is under construction at JQI. This apparatus is designed to create degnerate mixtures of bosonic rubidium ($^{87}$Rb) and fermionic lithium ($^{6}$Li). A degenerate Bose-Fermi mixture supports many quantum phase transitions, giving an experimental platform to study many-body statics, dynamics, and perhaps precision measurements. High T$_c$ superconductivity could be probed, where fermions are bound into Cooper pairs by boson mediated interactions. Dual species heteronuclear molecules with large permanent electric dipole moment may lead to a system for implementing quantum bits. A spin-polarized, non-interacting, degenerate $^{6}$Li gas coupled to $^{87}$Rb atoms in an optical lattice will give rise to a long range, spin-dependent interactions to realize quantum magnetism and potentially supersolidity. Far red-detuned lattices are far weaker, in recoil units, for Li as compared to Rb. So, in the Mott phase of Rb - one atom per lattice site - the three body recombination of Li-Li-Rb is greatly suppressed. Thus the wide $^{87}$Rb-$^{6}$Li Fesbach resonance at 1.1 kG is expected to effectively control fermion mediated interactions.