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arXiv · 2505.04854

Spontaneous Raman scattering out of a metastable atomic qubit

I. D. Moore·A. Quinn·J. O'Reilly·J. Metzner·S. Brudney·G. J. Gregory·D. J. Wineland·D. T. C. Allcock
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Abstract

Metastable qubits in atomic systems can enable large-scale quantum computing by simplifying hardware requirements and adding efficient erasure conversion to the pre-existing toolbox of high-fidelity laser-based control. For trapped atomic ions, the fundamental error floor of this control is given by spontaneous Raman and Rayleigh scattering from short-lived excited states. We measure spontaneous Raman scattering rates out of a metastable $D_{5/2}$ qubit manifold of a single trapped $^{40}$Ca$^+$ ion illuminated by 976 nm light that is -44 THz detuned from the dipole-allowed transition to the $P_{3/2}$ manifold. This supports the calculation of error rates from both types of scattering during one- and two-qubit gates on this platform, thus demonstrating that infidelities $<10^{-4}$ are possible.

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I. D. Moore, A. Quinn, J. O'Reilly, J. Metzner, S. Brudney, G. J. Gregory, D. J. Wineland, D. T. C. Allcock. 2025-05-07. Spontaneous Raman scattering out of a metastable atomic qubit. https://doi.org/10.1103/vlz1-s6zl

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