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

The authors have investigated the production of singly charged Yb⁺ 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⁺ 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 S₁2/ F = 0 state, by resonantly driving the S₁2/ - P₁2/ transition.