The recently demonstrated trapping and laser cooling of ¹³³Ba⁺ 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 ²P_3/2 and ²D_5/2 hyperfine splittings, as well as the ²P_3/2 ↔ ²S_1/2 and ²P_3/2 ↔ ²D_5/2 transition frequencies. Using these transitions, we demonstrate high-fidelity ¹³³Ba⁺ 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 \({\mathcal{F}}=0.99971(3)\), a factor of ≈2 improvement over the best reported performance of any qubit.

最近展示的¹³³ Ba ^+的俘获和激光冷却为将这种近乎理想的原子用于量子信息处理打开了大门。然而，在可以执行高保真量子比特操作之前，需要许多未知状态能量。在这里，我们报告的测量值² P _3/2和² d _5/2的超精细分裂，以及在² P _3/2  ↔  ²小号_1/2和² P _3/2  ↔  ² d _5/2过渡频率。使用这些过渡，我们演示了高保真¹³³Ba ⁺超精细量子位操纵与电子搁置检测，可用于基准量子位状态制备和测量（SPAM）。使用单次阈值歧视，我们测量的平均SPAM保真度为\（{\ mathcal {F}} = 0.99971（3）\），这是比任何qubit的最佳报告性能提高≈2倍的因素。