Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, Tianjin, 300072, China.
Sci Rep. 2023 Mar 22;13(1):4688. doi: 10.1038/s41598-023-31787-2.
The novel weak-value-amplification (WVA) scheme of precision metrology is deeply rooted in the quantum nature of destructive interference between the pre- and post-selection states. And, an alternative version, termed as joint WVA (JWVA), which employs the difference-signal from the post-selection accepted and rejected results, has been found possible to achieve even better sensitivity (two orders of magnitude higher) under some technical limitations (e.g. misalignment errors). In this work, after erasing the quantum coherence, we analyze the difference-signal amplification (DSA) technique, which serves as a classical counterpart of the JWVA, and show that similar amplification effect can be achieved. We obtain a simple expression for the amplified signal, carry out characterization of precision, and point out the optimal working regime. We also discuss how to implement the post-selection of a classical mixed state. The proposed classical DSA technique holds similar technical advantages of the JWVA and may find interesting applications in practice.
新型弱值放大（WVA）精密测量方案根植于预选择态和后选择态之间破坏性干涉的量子本质。并且，有一种称之为联合弱值放大（JWVA）的可选方案，它采用了后选择态被接受和拒绝的结果之间的差值信号，在某些技术限制下（例如失准误差），已经发现有可能实现更好的灵敏度（高两个数量级）。在这项工作中，在消除量子相干之后，我们分析了差信号放大（DSA）技术，它作为 JWVA 的经典对应物，并表明可以实现类似的放大效果。我们得到了放大信号的简单表达式，对精度进行了特征描述，并指出了最优工作模式。我们还讨论了如何在后选择态中实现经典混合态。所提出的经典 DSA 技术具有与 JWVA 类似的技术优势，可能在实际应用中具有有趣的应用。
