Trapping Yb atoms for an EDM Experiment
Reina Maruyama, Norval Fortson, Michael Romalis, University of Washington
We are investigating the possible use of a magneto-optical trap (MOT) and optical dipole trap to search for the CP-violating permanent electric dipole moment (EDM) by nuclear spin resonance in Yb (ytterbium) atoms. Optical cooling and trapping of Yb offers many advantages for an atomic EDM experiment including long spin-relaxation lifetimes and a zero average motional magnetic field vxE. The ultra-high vacuum necessary for the trap suppresses spurious magnetic fields due to leakage currents and will allow us to apply a high electric field. Similar EDM experiments have been proposed for the trapped heavy atoms Cs and Fr. However, the Yb-171 atoms are free from the large cross-sections for cold atom collisions that limit the sensitivity of the Cs and Fr experiments because Yb is diamagnetic with a spin-1/2 nucleus. We will use the 1S0 -> 1P1 (398.9 nm) transition for cooling and trapping. The 1P1 state has a relatively short lifetime of 5 ns, allowing a large laser cooling force to be applied to the atoms. The transition is almost a closed 2-state system, minimizing the need for an extra cleanup laser. We have frequency doubled a Ti:Sapphire laser with an LBO crystal to 398.9 nm and have observed fluorescence from this transition in a Yb beam. We have completed the initial studies for building the MOT and will discuss further progress and possible future experiments.
Go to the first page of the talk...