Efficient photoionisation, preparation and coherent manipulation of trapped /sup 171/Yb/sup +/-ions

The authors have investigated the production of singly charged Yb/sup +/ ions by photoionisation of Yb atoms in the gas phase and compared its efficiency with the ionisation by electron collision. In order to be able to prepare Yb/sup +/ ions in arbitrary coherent superposition states (single qubit gates) of the two hyperfine levels that serve as a qubit, the ions first have to be optically pumped into one of the two states, here into the S/sub 1/2/ F = 0 state, by resonantly driving the S/sub 1/2/ - P/sub 1/2/ transition.