Detecting nonlocality in many-body quantum states
Detecting nonlocality in many-body quantum states
复制标题
DOI：
10.1126/science.1247715
复制
发表时间：
2013-06
期刊：
影响因子：
56.9
通讯作者：
Jordi Tura i Brugués;R. Augusiak;A. B. Sainz;T. Vértesi;M. Lewenstein;A. Acín
中科院分区：
文献类型：
--
作者：
Jordi Tura i Brugués;R. Augusiak;A. B. Sainz;T. Vértesi;M. Lewenstein;A. Acín
量子力学系统的遥远部分可以以无法经典描述的方式相互关联——这是一个被称为非局部性的概念。Tura等人提出了一个简单的多粒子系统非定域性测试。该测试涉及的量应该很容易测量，例如，冷原子实验。这是对目前可用的测试的改进，这些测试很难在实验中实现。对于具有多粒子的系统，导出了一种简化的、实验上可获得的贝尔不等式形式。深入研究纠缠特性对我们理解量子多体系统至关重要。相比之下，人们对量子非定域性在这些系统中的作用知之甚少，因为现有的多部贝尔不等式涉及许多粒子之间的相关性，而这些相关性很难通过实验获得。我们构建了只涉及两体相关的多部贝尔不等式，并展示了它们如何揭示与核和原子物理相关的多体系统中的非定域性。我们的不等式可以被任意数量的粒子违反，并且可以通过测量总自旋分量来测试，从而为多体非定域性的实验检测开辟了道路，例如原子系综。
Testing nonlocality for many particles Distant parts of a quantum-mechanical system can be correlated in ways that cannot be described classically—a concept known as nonlocality. Tura et al. propose a simple test for nonlocality in systems with multiple particles. The test involves quantities that should readily be measurable in, for example, cold atom experiments. This is an improvement over currently available tests, which are difficult to implement experimentally. Science, this issue p. 1256 A simplified, experimentally accessible form of Bell inequalities is derived for systems with many particles. Intensive studies of entanglement properties have proven essential for our understanding of quantum many-body systems. In contrast, much less is known about the role of quantum nonlocality in these systems because the available multipartite Bell inequalities involve correlations among many particles, which are difficult to access experimentally. We constructed multipartite Bell inequalities that involve only two-body correlations and show how they reveal the nonlocality in many-body systems relevant for nuclear and atomic physics. Our inequalities are violated by any number of parties and can be tested by measuring total spin components, opening the way to the experimental detection of many-body nonlocality, for instance with atomic ensembles.