Cooling and trapping of ultracold strontium isotopic mixtures

We present the simultaneous cooling and trapping of an isotopic mixture in a magneto-optical trap and describe the transfer of the mixture into a conservative, far-off-resonant dipole trap. The mixture is prepared with a technique that applies to intermediate and heavy alkaline-earth-metal-like atoms. In this work, ${}^{88}\mathrm{Sr}$ and ${}^{86}\mathrm{Sr}$ are simultaneously loaded first into the magneto-optical trap operated on the ${}^{1}S_0\text{−}{}^{3}P_1$ spin-forbidden line at 689 nm, and then transferred into the dipole trap. We observe fast interspecies thermalization in the dipole trap which allows one to set a lower bound on the ${}^{88}\mathrm{Sr}\text{−}{}^{86}\mathrm{Sr}$ elastic cross section.