Entanglement and Quantum Non-Locality

纠缠和量子非定域性

• 批准号: EP/G048975/1
• 负责人: Nicolas Brunner
• 金额: $ 26.1万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FG048975%2F1
• 关键词: Entanglement; Quantum; Non; Locality

The aim of this project is to gain a deeper understanding of two fundamental concepts of quantum physics: entanglement and non-locality. The evolution of both of these concepts during the last century is remarkable. While Einstein considered them as an evidence of the failure of quantum mechanics, they are now recognized as an amazingly powerful resource for processing information. They are at the core of Quantum Information Science, which has established itself as a new branch of modern physics. Entanglement is a quantum property that has no classical analog. Entangled states have the striking property that they can be used to establish non-local correlations. In other words, correlations that cannot be reproduced by any physical model that behaves locally, as shown by Bell in the 1960s. Today the situation is even more exciting, since it has been realized that non-locality and entanglement, for long considered as being different facets of the same phenomenon, are in fact very different concepts and resources. This new line of research is based on a pioneering work of Popescu and Rohrlich, who showed that there are nonsignaling correlations (correlations that do not permit to send information faster than light) that are more non-local than those of quantum physics. The project has three main objectives. First, it will focus on the relation between the concepts of entanglement and non-locality. Roughly speaking, entanglement is the resource for processing quantum information, while non-locality provides a good measure of its computational power. Indeed, it is crucial for Quantum Information Science to have a deep understanding between the resource and the power it offers. Here, the problem will be addressed using the idea of simulating entangled states. In other words, to construct an alternative model to quantum theory, that predicts the same result for any measurements performed on an entangled state. Then, the project will address the problem of testing the Hilbert space dimension. The Hilbert space is the abstract mathematical framework for describing quantum states. As intuition suggests, the dimension of this space is directly related to the complexity of the state, and also to its uselfulness for processing information. Here, the goal will be to find efficient techniques for testing the Hilbert space dimension of an unknown quantum system. Finally this research will explore the possibility to test entanglement in macroscopic physical systems, which is still a grand challenge. Indeed, while it may be acceptable that tiny particles have very counter-intuitive properties (such as entanglement), it becomes far more difficult to conceive for macroscopic objects. The goal of this research will be to find physical systems well-suited for an experimental demonstration of entanglement on the macroscopic level. This research will shine new light on the foundations of quantum physics, but will also to provide potentially useful application in Quantum Information Science.

这个项目的目的是为了更深入地理解量子物理学的两个基本概念：纠缠和非定域性。这两个概念在上个世纪的演变是显著的。虽然爱因斯坦认为它们是量子力学失败的证据，但它们现在被认为是处理信息的一种惊人的强大资源。它们是量子信息科学的核心，量子信息科学已成为现代物理学的一个新分支。纠缠是一种没有经典类比的量子特性。纠缠态有一个惊人的特性，那就是它们可以用来建立非局域关联。换句话说，正如贝尔在20世纪60年代所表明的那样，任何局部行为的物理模型都无法再现这种相关性。今天的情况更加令人兴奋，因为人们已经认识到，非定域性和纠缠，长期以来被认为是同一现象的不同方面，实际上是非常不同的概念和资源。这条新的研究路线是基于波佩斯库和罗利希的一项开创性工作，他们表明存在非信号相关性（不允许发送比光更快的信息的相关性），这些相关性比量子物理学的非局域性更强。该项目有三个主要目标。首先，它将集中讨论纠缠和非定域性概念之间的关系。粗略地说，纠缠是处理量子信息的资源，而非局部性提供了一个很好的衡量其计算能力的指标。事实上，对量子信息科学来说，在资源和它提供的能力之间有一个深刻的理解是至关重要的。在这里，这个问题将使用模拟纠缠态的思想来解决。换句话说，构建一个替代量子理论的模型，预测在纠缠态上进行的任何测量的相同结果。然后，该项目将解决希尔伯特空间维度的测试问题。希尔伯特空间是描述量子态的抽象数学框架。直觉告诉我们，这个空间的维度直接关系到状态的复杂性，也关系到它对信息处理的有用性。在这里，目标将是找到有效的技术来测试未知量子系统的希尔伯特空间维度。最后，本研究将探索在宏观物理系统中测试纠缠的可能性，这仍然是一个巨大的挑战。事实上，虽然微小粒子具有非常违反直觉的特性（如纠缠）是可以接受的，但对于宏观物体来说，这就变得更加难以想象了。这项研究的目标将是找到非常适合在宏观层面上进行纠缠实验演示的物理系统。这项研究将为量子物理学的基础带来新的亮点，同时也将为量子信息科学提供潜在的有用应用。