Buffer-gas loaded MOTs for Ho, Yb,Tm, and Er

We report on direct loading of lanthanide atoms into MOTs from a two-stage slow buffer-gas beam source, which has a peak forward velocity of $\sim$ 30 - 60 m/s [1], considerably lower than other beam implementations. The low velocity combined with species generality makes this source useful for loading magneto-optical traps (MOTs), especially for species that are not well suited to the traditional approach of oven plus Zeeman slower. We report loading MOTs with Yb, Tm, Er, and Ho, without any additional slowing stages. Application of a single frequency slowing laser to the buffer-gas beam of Yb results in an unprecedentedly high loading rate of $2.0(1.0) \times 10^{10}$ Yb atoms/s and $1.3(0.7)\times 10^8$ Yb atoms in the MOT [2]. We plan to use this versatile source to load a MOT with CaF, following the same general approach to that used with YO and SrF [3, 4].\\[4pt] [1] N. R. Hutzler, et al., Chem. Rev. 112, 4803 (2012).\\[0pt] [2] B. Hemmerling, et al., arXiv:1310.3239.\\[0pt] [3] M. T. Hummon, et al., Phys. Rev. Lett. 110, 143001 (2013).\\[0pt] [4] E. F. Shuman, et al., Nature 467, 820 (2010).