发表机构
Shenzhen University; Sun Yat-Sen University (Zhuhai Campus); Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong)（深圳大学; 中山大学（珠海校区）; 粤港澳大湾区量子科学中心（广东））
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出一种仅用单次量子干涉测量即可实现量子双锁相检测的通用协议，通过顺序正交周期性多脉冲序列提取振荡信号的振幅、频率和初始相位，并在GHZ态下达到海森堡极限精度。
AI 中文摘要
振荡信号的高精度测量是基础科学中的普遍问题，也是实际技术中的关键任务。在量子计量学中，量子锁相检测为测量此类信号提供了一种有效方法。通常，当振荡信号的初始相位未知时，量子双锁相检测可以有效提取关于信号振幅、频率和初始相位的完整信息。传统的量子双锁相检测需要两次独立的量子干涉测量，每次都必须经历态制备和读出。然而，在实际实验中，态制备和读出的时间不必是可忽略的。特别是，态制备的时间比传感时间更长。为了节省实验资源，仅通过单次量子干涉测量实现量子双锁相检测，同时仍提取关于信号振幅、频率和初始相位的完整信息，是具有挑战性的。在这里，我们提出了一种通用协议，通过顺序正交周期性多脉冲序列，仅通过单次量子干涉测量即可实现量子双锁相检测。特别地，如果输入态是Greenberger-Horne-Zeilinger态，并且在干涉测量期间应用两次基于相互作用的操作，则频率、振幅和初始相位的测量精度都可以接近海森堡极限。我们的研究为使用单次量子干涉测量振荡信号开辟了新途径，并为实现交变信号的海森堡极限检测提供了一种可行方法。
英文摘要
High-precision measurement of oscillating signal is a ubiquitous issue in fundamental science and a critical task in practical technologies. In quantum metrology, quantum lock-in detection provide an efficient method for measuring such signal. In general, when the initial phase of the oscillating signal is unknown,quantum double lock-in detection can effectively extract complete information about the signal's amplitude, frequency, and initial phase. Conventional quantum double lock-in detection requires two individual quantum interferometry, each of which must undergo state preparation and readout. However, the time for state preparation and readout need not be negligible in practical experiments. In particular, the time for state preparation is longer than the time for sensing. To save experimental resources, it is challenging to achieve quantum double lock-in detection just via a single quantum interferometry while still extracting complete information about the signal's amplitude, frequency, and initial phase. Here, we present a general protocol for achieving a quantum double lock-in detection just via a single quantum interferometry under a sequential orthogonal periodic multipulse sequences. In particular, if the input state is a Greenberger-Horne-Zeilinger state and two interaction-based operations are applied during interferometry, the measurement precisions for frequency, amplitude, and initial phase can both approach the Heisenberg limit. Our study paves a new way for measuring oscillating signals with a single quantum interferometry, and provides a feasible method for achieving Heisenberg-limited detection of alternating signals.
