Spectroscopy of a Synthetic Trapped Ion Qubit

Author(s): Hucul, D; Christensen, JE; Hudson, ER; Campbell, WC | Abstract: © 2017 American Physical Society. Ba133+ 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 62P1/2↔62S1/2 and 62P1/2↔52D3/2 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 62P1/2↔52D3/2 electronic transition isotope shift for the rare A=130 and 132 barium nuclides, completing the spectroscopic characterization necessary for laser cooling all long-lived barium II isotopes.