Köhnke S, Agudelo E, Schünemann M, Schlettwein O, Vogel W, Sperling J, Hage B
Arbeitsgruppe Experimentelle Quantenoptik, Institut für Physik, Universität Rostock, D-18051 Rostock, Germany.
Institute for Quantum Optics and Quantum Information-IQOQI Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria.
Phys Rev Lett. 2021 Apr 30;126(17):170404. doi: 10.1103/PhysRevLett.126.170404.
Dissimilar notions of quantum correlations have been established, each being motivated through particular applications in quantum information science and each competing for being recognized as the most relevant measure of quantumness. In this contribution, we experimentally realize a form of quantum correlation that exists even in the absence of entanglement and discord. We certify the presence of such quantum correlations via negativities in the regularized two-mode Glauber-Sudarshan function. Our data show compatibility with an incoherent mixture of orthonormal photon-number states, ruling out quantum coherence and other kinds of quantum resources. By construction, the quantumness of our state is robust against dephasing, thus requiring fewer experimental resources to ensure stability. In addition, we theoretically show how multimode entanglement can be activated based on the generated, nonentangled state. Therefore, we implement a robust kind of nonclassical photon-photon correlated state with useful applications in quantum information processing.
已经建立了不同的量子关联概念，每种概念都由量子信息科学中的特定应用所推动，并且都在争夺被认可为最相关的量子性度量。在本论文中，我们通过实验实现了一种即使在没有纠缠和量子失协的情况下也存在的量子关联形式。我们通过正则化双模格劳伯 - 苏达尚函数中的负值来证明这种量子关联的存在。我们的数据表明与正交归一化光子数态的非相干混合兼容，排除了量子相干性和其他种类的量子资源。通过构造，我们状态的量子性对退相具有鲁棒性，因此需要较少的实验资源来确保稳定性。此外，我们从理论上展示了如何基于所生成的非纠缠态来激活多模纠缠。因此，我们实现了一种在量子信息处理中有实用应用的鲁棒的非经典光子 - 光子关联态。
