多体量子非定域性研究

Quantum nonlocality exhibits the important difference between classical physics and quantum physics. Moreover it is one of the key concepts in quantum information science. Currently many investigations concern on bipartite nonlocality, while the research on multipartite nonlocality just begins. This project focuses on multipartite nonlocality and its applications, especially for genuine multipartite case. The main context includes the classification and detection of multipartite nonlocality, the equivalency between the multipartite quantum entanglement and multipartite nonlocality for pure states, the nonlocality of important multipartite quantum states such as graph states, the relationship between nonlocality and some important concepts on quantum information theory, as well as the applications of multipartite nonlocality on quantum information processing, in particular on various device-independent protocols. The deep research on nonlocality will give the better understanding on the advantage afforded by quantum information processing, and advance the practical protocols in this field.

量子非定域性展现了量子物理和经典物理的重要区别，是量子信息学里的核心概念之一。目前两体非定域性的研究已经很多，而多体非定域性的研究刚刚起步。本项目将重点研究多体非定域性尤其是真正多体非定域性的性质及其应用。包括多体非定域性的分类及探测；在纯态情况下，多体量子纠缠与多体非定域性的等价性问题；一些重要的多体量子态如图态的非定域性质；非定域性与量子信息理论中的一些重要概念的联系等。同时也考察多体非定域性在量子信息处理过程中一些重要应用，尤其是在与设备无关的各种协议方面。对非定域性的深入研究将更好地理解量子信息处理所带来的优势，从而推动一些实用的量子信息处理方案的进展。

量子非定域性是量子物理和量子信息学里的核心概念之一。和多体量子纠缠相似，多体量子非定域性展现了丰富和复杂的结构。在本项目中，我们研究了多体量子非定域性的分类和探测。我们提出了无信号关联下m locality的定义。对应于从标准多体到真正多体的不同层级下的多体量子非定域性，我们系统地构造了一系列的的贝尔不等式和无不等式的Hardy类型测试的探测方法。我们还研究了有噪音情况下的一些重要的纠缠态如GHZ态和W态的多体量子非定域性的探测。这些研究成果，加深和拓展了对多体量子非定域性的理解，对于量子信息基础理论尤其是多体量子关联的进一步深入研究具有较强的意义。