The development of qualitatively new measurement capabilities is often a prerequisite for critical scientific and technological advances. Here we introduce an unconventional quantum probe, an entangled neutron beam, where individual neutrons can be entangled in spin, trajectory and energy. The spatial separation of trajectories from nanometers to microns and energy differences from peV to neV will enable investigations of microscopic magnetic correlations in systems with strongly entangled phases, such as those believed to emerge in unconventional superconductors. We develop an interferometer to prove entanglement of these distinguishable properties of the neutron beam by observing clear violations of both Clauser-Horne-Shimony-Holt and Mermin contextuality inequalities in the same experimental setup. Our work opens a pathway to a future of entangled neutron scattering in matter.

中文翻译：

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通过微观地纠缠中子来揭示上下文现实。

质量上新的测量能力的发展通常是关键科学技术进步的先决条件。在这里，我们介绍了一种非常规的量子探针，即纠缠的中子束，其中各个中子可以纠缠在自旋，轨迹和能量中。轨迹从纳米到微米的空间分离以及从peV到neV的能量差将使人们能够研究具有强纠缠相的系统中的微观磁相关性，例如那些被认为是在非常规超导体中出现的系统。我们开发了一种干涉仪，通过观察在相同的实验装置中对Clauser-Horne-Shimony-Holt和Mermin上下文不等式的明显违反，证明了中子束的这些可分辨特性的纠缠。