Zeeman slowing of a group-III atom

We realize a Zeeman slower of an atom in main group III of the Periodic Table, otherwise known as the “triel elements.” Despite the fact that our atom of choice (namely indium) does not have a ground state cycling transition suitable for laser cooling, slowing is achieved by driving the transition | 5 P 3 / 2 , F = 6 (cid:105) → | 5 D 5 / 2 , F = 7 (cid:105) , where the lower-energy state is metastable. Using a slower based on permanent magnets in a transverse-field configuration, we observe a bright slowed atomic beam at our design goal velocity of 70 m/s. The techniques presented here can straightforwardly extend to other triel atoms such as thallium, aluminum, and gallium. Furthermore, this work opens the possibility of cooling group-III atoms to ultracold temperatures. Slowing is accomplished with a 326 nm laser, two 410 nm repumpers, and two 451 nm repumpers, all of which are combined using dichroic mirrors (DM) and sent through the Zeeman slower. An independent 326 nm probe laser intersects with the atomic beam at θ = 45 ◦ in the science chamber. To measure the longitudinal atomic velocity distribution, fluorescence is collected with an EMCCD camera.