近日，浙江师范大学的高先龙课题组与合作者取得一项新进展。经过不懈努力，他们探究了亚普朗克结构和压缩真空态叠加中添加光子或减去光子的敏感性。相关研究成果已于2023年5月25日在国际知名学术期刊《物理评论A》上发表。

据悉，指南针态是四个相干态的叠加，其维格纳函数在相空间中形成了比普朗克尺度 ? 更小的结构，这些结构对于确定这些态对相空间位移的敏感性至关重要。

附：英文原文

Title: Sub-Planck structures and sensitivity of the superposed photon-added or photon-subtracted squeezed-vacuum states

Author: Naeem Akhtar, Jizhou Wu, Jia-Xin Peng, Wu-Ming Liu, Gao Xianlong

Issue&Volume: 2023/05/25

Abstract: The Wigner function of the compass state (a superposition of four coherent states) develops phase-space structures of dimension much less than the Planck scale $?$ , which are crucial in determining the sensitivity of these states to phase-space displacements. In the present work we introduce compasslike states that may have connection to the contemporary experiments, which are obtained by either adding photons to or subtracting photons from the superposition of two squeezed-vacuum states. We show that when a significant quantity of photons is added (or subtracted), the Wigner functions of these states are shown to have phase-space structures of an area that is substantially smaller than the Planck scale. In addition, these states exhibit sensitivity to displacements that is much higher than the standard quantum limit. Finally, we show that both the size of the sub-Planck structures and the sensitivity of our states are strongly influenced by the average photon number, with the photon-addition case having a higher average photon number leading to the smaller sub-Planck structures and, consequently, being more sensitive to displacement than the photon-subtraction case. Our states offer unprecedented resolution to the external perturbations, making them suitable for quantum sensing applications.

DOI: 10.1103/PhysRevA.107.052614

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.107.052614