Magneto-optical trap of titanium atoms

We realize a magneto-optical trap (MOT) of titanium (Ti) atoms, performing laser cooling on the 498 nm transition between the long-lived 3d3(F4)4sa5F5 metastable state and the 3d3(F4)4py5G6o excited state. Without the addition of any repumping light, we observe MOTs of the three stable, I=0 bosonic isotopes, Ti46, Ti48, and Ti50. Up to 8.30(26)×105Ti48 atoms are trapped at a maximum density of 1.3(4)×1011cm-3 and at a temperature of 90(15)μK. By measuring the decay of the MOT, we constrain the leakage branching ratio of the cooling transition (≤2.5×10-6) and the two-body loss coefficient (≤2×10-10cm3s-1). Our approach to laser cooling Ti can be applied to other transition metals, enabling a significant expansion of the elements that can be laser cooled.