Spectroscopy of Ho atoms and optical pumping for initialization of a collectively encoded quantum register

We will present results on spectroscopy of the 410.5 nm cooling transition in Ho using a source based on a frequency doubled diode laser. A laser cooled Ho sample is suitable for collective encoding of a large quantum register in the 128 hyperfine ground states. We have studied hybrid optical/microwave approaches for optical pumping into a single Zeeman sublevel and will present calculations showing the feasibility of high purity state preparation as a precursor for quantum gate operations.