Buffer gas loaded magneto-optical traps for Yb, Tm, Er and Ho

Abstract

Direct loading of lanthanide atoms into magneto-optical traps (MOTs) from a very slow cryogenic buffer gas beam source is achieved, without the need for laser slowing. The beam source has an average forward velocity of 60–$70;{\rm m};{{{\rm s}}^{-1}}$ and a velocity half-width of $\sim 35;{\rm m};{{{\rm s}}^{-1}}$, which allows for direct MOT loading of Yb, Tm, Er and Ho. Residual helium background gas originating from the beam results in a maximum trap lifetime of about 80 ms (with Yb). The addition of a single-frequency slowing laser applied to the Yb in the buffer gas beam increases the number of trapped Yb atoms to $1.3\left( 0.7 \right)\times {{10}^{8}}$ with a loading rate of $2.0\left( 1.0 \right)\times {{10}^{10}};{\rm atoms};{{{\rm s}}^{-1}}$. Decay to metastable states is observed for all trapped species and decay rates are measured. Extension of this approach to the loading of molecules into a MOT is discussed.

Journal
New Journal of Physics 16, 063070 (2014)
DOI