Degenerate Bose-Fermi mixtures of rubidium and ytterbium

We report the realization of a quantum degenerate mixture of bosonic $^{\mathrm{87}}$Rb and fermionic $^{\mathrm{171}}$Yb atoms in a hybrid optical dipole trap with a tunable, species-dependent trapping potential. $^{\mathrm{87}}$Rb is shown to be a viable refrigerant for the non-interacting $^{\mathrm{171}}$Yb atoms, cooling up to 2.4$\times $10$^{\mathrm{5}}$ Yb atoms to a temperature of T/T$_{\mathrm{F}}=$0.16(2) while simultaneously forming a $^{\mathrm{87}}$Rb Bose-Einstein condensate of 3.5$\times $10$^{\mathrm{5}}$ atoms. Furthermore we demonstrate our ability to independently tailor the potentials for each species, which paves the way for studying impurities immersed in a Bose gas.