Hyperfine and Optical Barium Ion Qubits

Abstract

State preparation, qubit rotation, and high fidelity readout are demonstrated for two separate \baseven qubit types. First, an optical qubit on the narrow 6S${}_{1/2}$ to 5D${}_{5/2}$ transition at 1.76 $\hat{I}¼$m is implemented. Then, leveraging the techniques developed there for readout, a ground state hyperfine qubit using the magnetically insensitive transition at 8 GHz is accomplished.