AI 中文总结
该研究通过光学实验提供量子事件违反局域动量守恒的反事实证据，发现超振荡区域提取的光子平均横向动量与守恒界限不符，高动量光子速率超预测，或为不依赖纠缠的新型量子非局域性首个实例。
AI 中文摘要
能量和动量等物理守恒定律通常被认为在时空范围内（包括量子现象中）精确且局域成立。然而，Aharonov、Popescu和Rohrlich（APR）最近基于一项思想实验提出，与系综平均不同，单个量子事件可能偶尔违反局域守恒定律。他们的论证依赖于APR本人在30多年前发现的被称为“超振荡”的波动现象。本文提供了这种违反的实验证据：我们从光学涡旋核心附近的一个小型超振荡区域提取光子，结果显示这些光子的平均横向动量在统计上与局域动量守恒所隐含的一般界限不相容。该界限的推导仅需一个理论上充分支持的假设，即提取机制不会改变光子的平均横向动量。我们还检测到具有高横向动量的光子，其速率显著超过假设局域动量守恒的模型所预测的速率。由于这种违反只能通过反事实和后选择来确立，因此它不与相对论因果性冲突。我们的结果可能代表了一种独特形式的量子非局域性的首个例子，该形式并不明确依赖于纠缠。
英文摘要
Physical conservation laws, such as those of energy and momentum, are generally believed to hold exactly and locally in spacetime, including in quantum phenomena. Yet Aharonov, Popescu, and Rohrlich (APR) recently argued, on the basis of a thought experiment, that individual quantum events, unlike ensemble averages, may occasionally violate local conservation laws. Their argument relies on the wave phenomenon known as "superoscillations", which APR themselves discovered more than 30 years ago. Here we provide experimental evidence for such a violation. We extract photons from a small superoscillatory region near the core of an optical vortex and show that their mean transverse momentum is statistically incompatible with a general bound implied by local momentum conservation. The derivation of this bound requires only the theoretically well-supported assumption that the extraction mechanism does not alter the photons' mean transverse momentum. We also detect photons with high transverse momentum at a rate significantly exceeding that predicted by a model assuming local momentum conservation. Because this violation can be established only counterfactually and through postselection, it does not conflict with relativistic causality. Our results may represent the first example of a distinct form of quantum nonlocality that does not explicitly rely on entanglement.
Comments29 pages, including 9 pages of main paper plus 20 pages of appendices. 15 figures, including 4 figures main paper plus 11 figures of the appendices
