Rojkov Ivan, Layden David, Cappellaro Paola, Home Jonathan, Reiter Florentin
Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland.
Research Laboratory of Electronics and Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2022 Apr 8;128(14):140503. doi: 10.1103/PhysRevLett.128.140503.
The sensitivity afforded by quantum sensors is limited by decoherence. Quantum error correction (QEC) can enhance sensitivity by suppressing decoherence, but it has a side effect: it biases a sensor's output in realistic settings. If unaccounted for, this bias can systematically reduce a sensor's performance in experiment, and also give misleading values for the minimum detectable signal in theory. We analyze this effect in the experimentally motivated setting of continuous-time QEC, showing both how one can remedy it, and how incorrect results can arise when one does not.
量子传感器的灵敏度受退相干限制。量子纠错（QEC）可通过抑制退相干来提高灵敏度，但它有一个副作用：在实际环境中会使传感器输出产生偏差。如果不加以考虑，这种偏差会系统性地降低传感器在实验中的性能，并且在理论上也会给出关于最小可检测信号的误导性值。我们在连续时间量子纠错这个受实验启发的环境中分析了这种效应，既展示了如何纠正它，也展示了不这样做时如何产生错误结果。
