Spectroscopy of a Synthetic Trapped Ion Qubit

Ba-133(+) has been identified as an attractive ion for quantum information processing due to the unique combination of its spin-1/2 nucleus and visible wavelength electronic transitions. Using a microgram source of radioactive material, we trap and laser cool the synthetic A = 133 radioisotope of barium II in a radio-frequency ion trap. Using the same, single trapped atom, we measure the isotope shifts and hyperfine structure of the 6(2)P(1/2) <-> 6(2)S(1/2) and 6(2)P(1/2) <-> 5(2)D(3/2) electronic transitions that are needed for laser cooling, state preparation, and state detection of the clock-state hyperfine and optical qubits. We also report the 6(2)P(1/2) <-> 5(2)D(3/2) electronic transition isotope shift for the rare A = 0 and 132 barium nuclides, completing the spectroscopic characterization necessary for laser cooling all long-lived barium II isotopes.