通过次优测量稳定时间量子增强灵敏度
Stabilizing temporal quantum-enhanced sensitivity via sub-optimal measurements
- University of Electronic Science and Technology of China（电子科技大学）
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China（电子科技大学前沿科学与工程学院）
- Key Laboratory of Quantum Physics and Photonic Quantum Information, Ministry of Education, University of Electronic Science and Technology of China（教育部量子物理与光子量子信息重点实验室，电子科技大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文提出一种分组测量协议，在非平衡量子传感中消除次优测量的振荡，实现稳健的二次时间缩放，从而稳定量子增强灵敏度。
AI中文摘要：
在非平衡探测中，量子增强灵敏度通过精度相对于时间的超线性缩放来量化，这是一种核心计量资源。然而，这需要最优测量，而最优测量通常复杂且依赖于时间，在实践中具有挑战性。次优测量通常无法保持稳健的超线性缩放，并表现出振荡。在此，我们首先在一般多参数非平衡量子传感框架中建立普适的时间缩放定律。在此设定下，我们识别出次优测量下传感精度的普适行为，该行为表现为由额外有界振荡函数调制的二次缩放。为了消除振荡部分，我们提出一种协议，将测量分为不同组，每组在不同时间进行。该协议获得的集体精度即使在多参数体制下的次优测量中也能稳定稳健的二次缩放。我们通过三个不同的示例以及贝叶斯估计验证了我们的协议。我们的协议适用于所有信息性测量，并向量子增强灵敏度的实际实现迈出了关键一步。
英文摘要：
In non-equilibrium probes, quantum-enhanced sensitivity is quantified through super-linear scaling of precision with respect to time, as a central metrology resource. However, this requires optimal measurements, which are often complex and time-dependent, making it challenging in practice. Sub-optimal measurements typically fail to retain robust super-linear scaling and show oscillations. Here, we begin by establishing a universal temporal scaling law in a general multi-parameter non-equilibrium quantum sensing framework. Within this setting, we identify the universal behavior of the sensing precision with sub-optimal measurements which shows quadratic scaling modulated by an additional bounded oscillatory function. To remove the oscillatory part, we propose a protocol in which measurements are partitioned into different groups, each performed at different times. The collective precision obtained from this protocol stabilizes a robust quadratic scaling even for sub-optimal measurements in the multi-parameter regime. We validate our protocol through three distinct examples as well as Bayesian estimation. Our protocol is applicable to every informative measurement and takes a key step towards practical realization of quantum-enhanced sensitivity.
