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arXiv · 1907.13331

High fidelity manipulation of a qubit built from a synthetic nucleus

Justin E. Christensen·David Hucul·Wesley C. Campbell·Eric R. Hudson
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Abstract

The recently demonstrated trapping and laser cooling of $^{133}$Ba$^+$ 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 $^2$P$_{3/2}$ and $^2$D$_{5/2}$ hyperfine splittings, as well as the $^2$P$_{3/2}$$\leftrightarrow$ $^2$S$_{1/2}$and $^2$P$_{3/2}$ $\leftrightarrow$ $^2$D$_{5/2}$ transition frequencies. Using these transitions, we demonstrate high fidelity $^{133}$Ba$^+$ 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 $\mathcal{F} = 0.99971(6)$, a factor of $\approx$ 2 improvement over the best reported performance of any qubit.

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Justin E. Christensen, David Hucul, Wesley C. Campbell, Eric R. Hudson. 2019-07-31. High fidelity manipulation of a qubit built from a synthetic nucleus. https://doi.org/10.1038/s41534-020-0265-5

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