Lifetime of the Strongly Interacting Bose Gas
Magnetically-tunable Feshbach resonances allow one to change the atom-atom scattering properties in ultracold atomic gases to arbitrary strength and sign, subject only to limitations imposed by the finite temperature of the gas. Studies of Fermi gases taken directly to the atom-atom scattering resonance have led, among other results, to experimental investigations of BCS-BEC crossover physics which provide direct tests of theories of superconductivity. However, when bosonic gases are taken to the point of divergent scattering length, rapid three-body recombination limits the lifetime of the gas and can even break the criterion for maintaining thermal equilibrium throughout the ensemble of atoms.
In this talk, I will present recent experimental and theoretical work done at LKB/IFRAF in the group of Christophe Salomon on an ensemble of ultracold lithium-7 taken to a Feshbach scattering resonance. I will present a measurement of the lifetime of the gas at and around this scattering resonance and provide a framework with which to understand the loss process based on the theoretical work done by our colleagues in the group. I hope to provide some insight on how to think of three-body losses in the regime where the two-body interaction becomes arbitrarily large.