Title: Certifying nonlocal properties of noisy quantum operations Show Chinese title

Title: 认证噪声量子操作的非局域性质

Abstract: Certifying quantum properties from the probability distributions they induce is an important task for several purposes. While this framework has been largely explored and used for quantum states, its extrapolation to the level of channels started recently in a variety of approaches. In particular, little is known about to what extent noise can spoil certification methods for channels. In this work we provide a unified methodology to certify nonlocal properties of quantum channels from the correlations obtained in prepare-and-measurement protocols: our approach gathers fully and semi-device-independent existing methods for this purpose, and extends them to new certification criteria. In addition, the effect of different models of dephasing noise is analysed. Some noise models are shown to generate nonlocality and entanglement in special cases. In the extreme case of complete dephasing, the measurement protocols discussed yield particularly simple tests to certify nonlocality, which can be obtained from known criteria by fixing the dephasing basis. These are based on the relations between bipartite quantum channels and their classical analogues: bipartite stochastic matrices defining conditional distributions. Show Chinese abstract

Abstract: 从它们引起的概率分布中验证量子特性对于多个目的来说是一项重要任务。 虽然这一框架已被广泛探索并用于量子态，但将其推广到信道层面最近才在各种方法中开始出现。 特别是，关于噪声在多大程度上会破坏信道的验证方法，目前了解甚少。 在本工作中，我们提供了一种统一的方法，从准备和测量协议中获得的相关性来验证量子信道的非局域性质：我们的方法汇集了现有完全和半设备无关的方法，并将其扩展到新的验证标准。 此外，分析了不同去相位噪声模型的影响。 一些噪声模型被证明在特殊情况下会产生非局域性和纠缠。 在完全去相位的极端情况下，所讨论的测量协议可以产生特别简单的测试来验证非局域性，这些测试可以通过固定去相位基来从已知的标准中获得。 这些测试基于双变量量子信道与其经典对应物之间的关系：定义条件分布的双变量随机矩阵。