High-fidelity manipulation of a qubit enabled by a manufactured nucleus

The recently demonstrated trapping and laser cooling of Ba-133(+) has opened the door to the use of this nearly ideal atom for quantum information processing. However, before high-fidelity qubit operations can be performed, a number of unknown state energies are needed. Here, we report measurements of the P-2(3/2) and D-2(5/2) hyperfine splittings, as well as the P-2(3/2) <-> S-2(1/2) and P-2(3/2) <-> D-2(5/2) transition frequencies. Using these transitions, we demonstrate high-fidelity Ba-133(+) hyperfine qubit manipulation with electron shelving detection to benchmark qubit state preparation and measurement (SPAM). Using single-shot, threshold discrimination, we measure an average SPAM fidelity of F=0.99971(3), a factor of approximate to 2 improvement over the best reported performance of any qubit.