Two-color magneto-optical trapping of ytterbium atoms

We report laser cooling and trapping of ytterbium atoms in a two-color magneto-optical trap (MOT). Benefited from both the broad singlet transition (${}^1{\text{S}}_0\to {}^1{\text{P}}_1$) and the narrow intercombination transition (${}^1{\text{S}}_0\to {}^3{\text{P}}_1$) of ytterbium atoms, the two-color MOT enables rapid loading and efficient cooling. We systematically investigate the shielding effect of the intercombination transition by examining the atom loading and loss rates of single-color and two-color MOTs. Our findings are general and can be extended to other alkaline earth(-like) atoms.