Qubit state detection is an important part of a quantum computation. As the number of qubits in a quantum register increases, it is necessary to maintain high-fidelity detection to accurately measure the multiqubit state. Here we present experimental demonstration of high-fidelity detection of a multiqubit trapped-ion register with an average single-qubit detection error of 4.2(1.5) ppm and a four-qubit state detection error of 17(2) ppm, limited by the decay lifetime of the qubit, using a single-photon-sensitive camera with fast data collection, excellent temporal and spatial resolution, and low instrumental crosstalk.

中文翻译：

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捕获离子量子位寄存器的高保真同时检测

量子位状态检测是量子计算的重要组成部分。随着量子寄存器中量子位数量的增加，需要保持高保真检测以准确测量多量子位状态。在这里，我们展示了多量子位捕获离子寄存器的高保真检测实验演示，平均单量子位检测误差为 4.2(1.5) ppm，四量子位状态检测误差为 17(2) ppm，受衰减限制量子位的寿命，使用具有快速数据收集、出色的时间和空间分辨率以及低仪器串扰的单光子敏感相机。