Coherent three-photon process for creating metastable degenerate gasses of alkaline-earth-like atoms
Creating degenerate gasses of metastable alkaline-earth-like (AE) atoms is an outstanding challenge due to large inelastic losses that prevent direct evaporation in the metastable state. However, obtaining degenerate samples in a metastable state is necessary for some quantum simulation proposals, and could help to advance atomic structure calculations or enable the study of quadrupolar physics. Here, we present a coherent three-photon process to transfer degenerate AE atoms from the ground state to either 3P2 or 3P0. Simulations of the optical bloch equations show theoretical transfer efficiencies of >~ 90% using reasonable experimental parameters in both strontium and ytterbium. We end with a discussion of the experimental challenges that need to be overcome to successfully realize such transfer efficiencies.