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– − 70ms 1 and a velocity half-width of ∼ − 35 m 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 (0.7) 10 × 8 with a loading rate of × − 2.0 (1.0) 10 atoms s 10 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.