Signatures of many-particle interference
Signatures of many-particle interference
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DOI：
10.1088/1361-6455/ab5c30
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发表时间：
2019-08
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影响因子：
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通讯作者：
M. Walschaers
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文献类型：
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作者：
M. Walschaers
具有许多成分的量子系统引起了一系列概念，分析和计算挑战，因此，标签“复杂系统”。首先，人们可以认为由多体哈密顿量描述的相互作用是这种复杂性的根源。然而，人们逐渐清楚地认识到，即使没有相互作用，多体系统也不仅仅是其各部分的总和。这一特点是由于多体干涉。最著名的干涉现象之一是Hong-Ou-Mandel效应，其中观察到一对（非相互作用）相同光子的总相消干涉。这种双光子干涉效应可以推广到许多粒子的系统，这些粒子可以是费米子或玻色子。由此产生的多粒子干涉超越了玻色-爱因斯坦或费米-狄拉克分布中包含的量子统计效应，并且在本质上是动态的。这篇文章将介绍描述全同粒子系统的数学框架，并解释不可分割性的概念。然后，我们将把我们的注意力集中在自由粒子的动力学系统，并正式引入多粒子干涉的概念。它对多粒子跃迁概率的影响在计算上很难评估，并且对于具有大量相同粒子的系统来说，它变得非常棘手。因此，这将建立替代的，更有效的方法来观察多粒子干涉的签名。第一种类型的特征依赖于对发生在具有高度对称性的干涉仪中的高度敏感但也高度脆弱的完全相消干涉过程的检测。第二类签名是基于统计特征，当我们研究少量的干涉仪的输出端口之间的相关性的典型行为时出现的。我们最终将展示这些多粒子干涉的统计特征如何引导我们得到洪欧曼德尔效应的统计版本。本次研讨会上展示的作品是2018年DPG SAMOP学位论文奖的四个入围者之一。
Quantum systems with many constituents give rise to a range of conceptual, analytical and computational challenges, hence, the label ‘complex systems’. In the first place, one can think of interactions, described by a many-body Hamiltonian, as the source of such complexity. However, it has gradually become clear that, even in absence of interactions, many-body systems are more than just the sum of their parts. This feature is due to many-body interference. One of the most well-known interference phenomena is the Hong–Ou–Mandel effect, where total destructive interference is observed for a pair of (non-interacting) identical photons. This two-photon interference effect can be generalised to systems of many particles which can be either fermionic or bosonic. The resulting many-particle interference goes beyond quantum statistical effects that are contained in the Bose–Einstein or Fermi–Dirac distributions, and is dynamical in nature. This Tutorial will introduce the mathematical framework for describing systems of identical particles, and explain the notion of indistinguishability. We will then focus our attention on dynamical systems of free particles and formally introduce the concept of many-particle interference. Its impact on many-particle transition probabilities is computationally challenging to evaluate, and it becomes rapidly intractable for systems with large numbers of identical particles. Hence, this Tutorial will build up towards alternative, more efficient methods for observing signatures of many-particle interference. A first type of signatures relies on the detection of a highly sensitive -but also highly fragile- processes of total destructive interference that occurs in interferometers with a high degree of symmetry. A second class of signatures is based on the statistical features that arise when we study the typical behaviour of correlations between a small number of the interferometer’s output ports. We will ultimately show how these statistical signatures of many-particle interference lead us to a statistical version of the Hong–Ou–Mandel effect. The work presented in this Tutorial was one of the four shortlisted finalists of the 2018 DPG SAMOP dissertation prize.