Creation of a degenerate Bose-Bose mixture of erbium and lithium atoms

We report the realization of a degenerate mixture of ${}^{166}$Er and ${}^7$Li atoms in their energetically lowest spin states. The two species are sequentially laser-cooled and loaded into an optical dipole trap, then transported to a glass cell and simultaneously evaporated to degeneracy. Er serves as the coolant for Li, and we observe efficient sympathetic cooling facilitated by a large interspecies elastic scattering cross section. Three-body losses are found to be small, making this platform promising for the study of interacting mixtures with large mass imbalance.