Experiments in the Ultracold Lithium - Ytterbium System

Abstract

I detail the construction of an experimental apparatus created for performing ultracold atomic experiments with fermionic lithium-6 (Li) and several isotopes of ytterbium (Yb), and several of the first experiments performed using this apparatus. The apparatus consists of a vacuum chamber, laser and auxiliary systems, which together are used to produce the first instance of trapped ultracold mixtures of lithium and ytterbium. We show that the system is stable and obtain the <italic>s</italic>-wave scattering properties of Li-Yb collisions. By using Yb to sympathetically cool Li, double quantum degeneracy is achieved. I demonstrate the versatility of the new system with several experiments. In the first, we investigate the behvaiour of Li near a broad Feshbach resonance, and modify it with Yb. In the second, we produce Yb in the metastable state, and trap it in a 1064 nm optical dipole trap, which allows for a technically simple spin polarization procedure. We then characterize the dynamics of a Li - metastable Yb mixture. The work described in this thesis provides a pathway to future extensions such as the magentic tuning of Li-Yb interactions and the production of LiYb molecules by either photo- or magnetoassociation. The potential interest of this specific system lies in the combination of alkali and spin-singlet atom, leading to a potential paramagnetic ground state molecule, and experimental realizations of systems which cannot be accessed with bialkali experiments.