发表机构
Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO); European Laboratory for Non-linear Spectroscopy, Universitá di Firenze; Dipartimento di Fisica, Università di Genova; INFN - Sezione di Genova（意大利国家光学研究所; 佛罗伦萨大学非线性光谱学欧洲实验室; 热那亚大学物理系; 意大利国家核物理研究所热那亚分部）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出准时间无信号性概念，并据此定义宏观实在性的准概率表征，证明其蕴含时间无信号性但反之不成立，为测试宏观实在性提供更灵敏的工具。
AI 中文摘要
在本文中，我们引入了准时间无信号性（QNSIT）的概念，该概念将时间无信号性（NSIT）扩展到准概率分布。QNSIT要求所考虑的准概率分布在中间时刻的边缘分布不受一系列量子测量引起的测量反作用的影响。与QNSIT相关，我们提出了宏观实在性的准概率表征，${\ m MR}_{\ m qp}$，该表征要求QNSIT条件得到满足，并且由测量结果构建的准概率分布是正的。我们证明了${\ m MR}_{\ m qp}$蕴含NSIT，而反之则不成立，因为系统动力学产生或保留了隐藏的叠加路径。我们还证明了，对于二能级系统，${\ m MR}_{\ m qp}$和NSIT条件是一致的。因此，${\ m MR}_{\ m qp}$为测试宏观实在性提供了更灵敏的工具，并且可以通过量子非破坏性测量方案在实验上实现。
英文摘要
In this paper, we introduce the concept of quasi non-signaling in time (QNSIT), which extends non-signaling in time (NSIT) to quasiprobability distributions. QNSIT requires that the marginals of the quasiprobability distribution under consideration at intermediate times remain unperturbed by the measurement back-action induced by a sequence of quantum measurements. Associated with QNSIT, we propose a quasiprobabilistic characterization of macrorealism, ${\rm MR}_{\rm qp}$, which requires that both the QNSIT conditions are satisfied and the quasiprobability distribution constructed from the measurement outcomes is positive. We prove that ${\rm MR}_{\rm qp}$ implies NSIT, whereas the converse does not hold because of hidden superposition paths generated or preserved by the system dynamics. We also prove that, for a two-level system, the ${\rm MR}_{\rm qp}$ and NSIT conditions coincide. ${\rm MR}_{\rm qp}$ therefore provides a more sensitive tool for testing macrorealism and can be implemented experimentally through a quantum non-demolition measurement scheme.
Comments7 pages, 1 figure. Comments and feedback are welcome
