Qubits encoded in hyperfine states of trapped ions are ideal for quantum computation given their long lifetimes and low sensitivity to magnetic fields, yet they suffer from off-resonant scattering during detection, often limiting their measurement fidelity. In ${}^{171}{\text{Yb}}^{+}$ this is exacerbated by a low fluorescence yield, which leads to a need for complex and expensive hardware, a problematic bottleneck especially when scaling up the number of qubits. We demonstrate a detection routine based on electron shelving to address this issue in ${}^{171}{\text{Yb}}^{+}$ and achieve a $5.6\times$ reduction in single-ion detection error on an avalanche photodiode to $1.8\left(2\right)\times {10}^{-3}$ in a 100 $\mu \mathrm{s}$ detection period and a $4.3\times$ error reduction on an electron multiplying CCD camera with $7.7\left(2\right)\times {10}^{-3}$ error in 400 $\mu \mathrm{s}$. We further improve the characterization of a repump transition at 760 nm to enable a more rapid reset of the auxiliary ${}^2{F}_{7/2}$ states populated after shelving. Finally, we examine the detection fidelity limit using the long-lived ${}^2{F}_{7/2}$ state, achieving further $300\times$ and $12\times$ reductions in error to $6\left(7\right)\times {10}^{-6}$ and $6.3\left(3\right)\times {10}^{-4}$ in 1 ms on the respective detectors. While shelving-rate limited in our setup, we suggest various techniques to realize this detection method at speeds compatible with quantum information processing, providing a pathway to ultrahigh-fidelity detection in ${}^{171}{\text{Yb}}^{+}$.

中文翻译：

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通过 171Yb+ 中的 2D5/2 和 2F7/2 流形中的电子搁架进行可扩展的超精细量子位状态检测

以捕获离子的超精细状态编码的量子位由于其长寿命和对磁场的低敏感性而非常适合量子计算，但它们在检测过程中会遭受非共振散射，这通常会限制其测量保真度。在${}^{171}{\text{镝}}^{+}$低荧光产量加剧了这种情况，这导致需要复杂且昂贵的硬件，这是一个有问题的瓶颈，尤其是在扩大量子位数量时。我们展示了一个基于电子搁架的检测程序来解决这个问题${}^{171}{\text{镝}}^{+}$ 并达到一个 $5.6\times$ 降低雪崩光电二极管上的单离子检测误差 $1.8\left(2\right)\times {10}^{-3}$ 在 100 $\mu \mathrm{秒}$ 检测期和 $4.3\times$ 减少电子倍增 CCD 相机的误差 $7.7\left(2\right)\times {10}^{-3}$ 400 中的错误 $\mu \mathrm{秒}$. 我们进一步改进了 760 nm 处的再泵浦跃迁的表征，以实现更快速的辅助复位${}^2{F}_{7/2}$搁置后人口众多的州。最后，我们使用长寿命的${}^2{F}_{7/2}$ 状态，进一步实现 $300\times$ 和 $12\times$ 误差减少到 $6\left(7\right)\times {10}^{-6}$ 和 $6.3\left(3\right)\times {10}^{-4}$在 1 ms 内在各自的检测器上。虽然在我们的设置中搁置率受到限制，但我们提出了各种技术来以与量子信息处理兼容的速度实现这种检测方法，为实现超高保真检测提供了途径${}^{171}{\text{镝}}^{+}$.