Optical barium ion qubit
Dahyun Yum, D. De Munshi, Tarun Dutta, Manas Mukherjee · Journal of the Optical Society of America B · 2017
We demonstrate an optical single qubit based on a narrow 6S1/2 to 5D5/2 quadrupole transition of a single Ba+ ion operated by only diode-based lasers. The characteristic properties of the qubit are discussed. We observe continuous bit-flip oscillations at a rate of about 250 kHz, which is fast enough for a qubit operation as compared to the measured coherence time of over 3 ms. We also present a technique, called randomized benchmarking, to quantify the bit-flip error in each qubit NOT gate operation.