Strong notions of nonclassicality: experimental signatures and applications

强烈的非经典性概念：实验签名和应用

• 批准号: RGPIN-2017-04383
• 负责人: Spekkens, Robert
• 金额: $ 4.08万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=690675
• 关键词: Strong; notions; nonclassicality; experimental; signatures

Quantum theory underlies most of modern physics, but there is still no consensus about the manner in which it departs conceptually from classical theories. The question is not academic. For many tasks -- in particular in cryptography and computation -- quantum protocols outperform their classical counterparts, but poor intuitions about quantum theory impede our ability to harness its power. The problem is also acute for interdisciplinary research, as different branches of physics often use formulations of quantum theory that differ in their approaches to defining classicality. Finally, in emerging fields where quantum effects are thought to be significant, such as quantum biology and quantum machine learning, it remains unclear what must be demonstrated to establish that a given phenomenon resists classical explanation. All of this points to the need for a unified theory of nonclassicality that transcends fields and formulations. ***A good notion of nonclassicality should also be such that it can be subjected to a direct experimental test. This requires being able to infer constraints on experimental statistics directly from a set of classical principles. If an experiment is found to violate those constraints, then it follows that one or more of the principles must be violated in any theory that can do justice to the experiment, including any future successor to quantum theory. In other words, strong notions of nonclassicality are "future-proof".***The best prospect for a strong and unified notion of nonclassicality is the notion of contextuality. By these lights, an experiment admits of a classical explanation only if it admits of a model that is noncontextual, meaning that the representation of an experimental procedure in the model does not depend on any features of the procedure (termed "contexts") which are irrelevant to the observed statistics. Noncontextuality underlies the famous Kochen-Specker theorem and subsumes Bell's notion of local causality as a special case. For various paradigmatically quantum phenomena, such as interference, tunneling, particle statistics, teleportation, and so forth, I aim to determine precisely which of their features can be proven to be strongly nonclassical. I will develop techniques for deriving experimental signatures of strong nonclassicality that are robust to noise and imperfections. Finally, I intend to elucidate the sense in which strong nonclassicality is a resource, in particular, to better understand its applications to information processing and to determine whether it has applications for other sorts of tasks, such as developing high-precision sensors or optimally efficient heat engines. ***The PhD students working on this research program will acquire a deep understanding of the nature of quantumness and its potential applications to future technologies, positioning them well for careers in the growing field of quantum information science.

量子理论是大多数现代物理学的基础，但对于它在概念上如何与经典理论背道而驰，人们仍然没有达成共识。这个问题不是学术问题。对于许多任务--特别是在密码学和计算方面--量子协议的表现优于经典协议，但对量子理论糟糕的直觉阻碍了我们利用其力量的能力。对于跨学科研究来说，这个问题也很尖锐，因为物理学的不同分支经常使用不同的量子理论公式来定义经典。最后，在量子效应被认为显著的新兴领域，如量子生物学和量子机器学习，目前还不清楚必须证明什么才能证明给定的现象抵制经典解释。所有这些都表明，需要一种超越领域和公式的非古典主义统一理论。*一个好的非古典性概念也应该是这样的，它可以接受直接的实验测试。这需要能够直接从一套经典原理中推断出对实验统计数据的约束。如果一项实验被发现违反了这些限制，那么任何能够公平对待该实验的理论，包括任何未来量子理论的继任者，都必须违反其中的一项或多项原则。换句话说，强烈的非古典性概念是“经得起未来考验的”。*强而统一的非古典性概念的最好前景是语境性的概念。从这些方面来看，只有当实验承认一个模型是非上下文的时，它才能接受经典的解释，这意味着在模型中实验过程的表示不依赖于与观察到的统计数据无关的过程的任何特征(称为“上下文”)。非语境性是著名的柯兴-斯派克定理的基础，并将贝尔的局部因果关系概念作为特例包含在内。对于各种典型的量子现象，如干涉、隧道、粒子统计、隐形传态等等，我的目标是准确地确定它们中的哪些特征可以被证明是强烈的非经典特征。我将开发一些技术，以获得对噪音和瑕疵具有健壮性的强烈非古典性的实验签名。最后，我打算阐明强烈的非古典性是一种资源的意义，特别是为了更好地理解它在信息处理中的应用，并确定它是否适用于其他类型的任务，如开发高精度传感器或最佳效率的热机。*从事这一研究项目的博士生将对量子的本质及其对未来技术的潜在应用有深刻的理解，为他们在不断增长的量子信息科学领域的职业生涯奠定良好的基础。