论文标题
验证超出相位否定性的单模非经典性
Verifying single-mode nonclassicality beyond negativity in phase space
论文作者
论文摘要
尽管相空间中的消极情绪是非古典性的众所周知的签名，但各种非古典状态都需要其表征超出消极情绪。我们在相空间中建立了一个非经典性的框架，该框架通过直接的实验证据全面地解决了非经典状态。这包括作为特殊情况的相位空间分布的负性，并进一步分析具有阳性分布的量子状态。我们证明，它仅通过仅检查三个相位空间点来检测所有非经典高斯州和所有非高斯州的非高斯州。我们的形式主义还为基于痕量距离的非经典性度量提供了实验可访问的下限。重要的是，可以进一步适应这种基础方法，以分别通过一系列非理想的On-Ow-On-Owt探测器和粗粒粒的同源测量来构成两个方向上的实用测试。所有这些测试实际上都在可靠地针对噪声的非分类状态表征非分类状态，从而为量子技术中的各种量子系统提供了一种多功能工具。
While negativity in phase space is a well-known signature of nonclassicality, a wide variety of nonclassical states require their characterization beyond negativity. We establish a framework of nonclassicality in phase space that addresses nonclassical states comprehensively with a direct experimental evidence. This includes the negativity of phase-space distribution as a special case and further analyzes quantum states with positive distributions effectively. We prove that it detects all nonclassical Gaussian states and all non-Gaussian states of arbitrary dimension remarkably by examining three phase-space points only. Our formalism also provides an experimentally accessible lower bound for a nonclassicality measure based on trace distance. Importantly, this foundational approach can be further adapted to constitute practical tests in two directions looking into particle and wave nature of bosonic systems, via an array of nonideal on-off detectors and coarse-grained homodyne measurement, respectively. All these tests are practically powerful in characterizing nonclasssical states reliably against noise, making a versatile tool for a broad range of quantum systems in quantum technologies.
