近日，四川大学的张志友及其研究团队取得一项新进展。经过不懈努力，他们提出一种基于弱测量的伪自旋指针的具有成本效益的精确测量方案。相关研究成果已于2024年6月12日在国际知名学术期刊《物理评论A》上发表。

本文提出了一种针对微弱信号的精密测量方案，其核心在于一种基于弱测量的无量纲伪自旋指针，有效地将连续测量转换为离散测量。实验证明，在不测量参数分布的情况下，使用指针可以有效地恢复参数分布矩的弱扰动。

实验结果表明，当信号强度比面阵相机方法弱3 ~ 4个数量级时，测量精度提高了一个数量级。研究人员期望这种方法可以有效地加载到各种量子系统中，从而促进量子精密测量或量子计算的发展。

据悉，作为最先进的量子技术的重要组成部分，对快速高效的量子测量的需求也在日益增长。

附：英文原文

Title: Weak-measurement-based pseudospin pointer: A cost-effective scheme for precision measurement

Author: Ling Ye, Lan Luo, An Wang, Rongchun Ge, Zhiyou Zhang

Issue&Volume: 2024/06/12

Abstract: As an essential component of state-of-the-art quantum technologies, fast and efficient quantum measurements are in persistent demand over time. Here, we present a precision measurement scheme for weak signals. We propose a dimensionless pseudo-spin pointer based on weak measurement which effectively converts a continuous measurement into a discrete one. We demonstrate experimentally that a weak perturbation of the parametric distribution's moment can be retrieved efficiently by employing the pointer without measuring the distribution literally. The results show that for signals three to four orders weaker in strength than the area-array camera method, an order of improvement in precision is achieved experimentally. We expect that this method can be effectively loaded into various quantum systems and promote the development of quantum precision measurement or quantum computing.

DOI: 10.1103/PhysRevA.109.L060601

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.L060601