Chemical reactions, where bonds break and form, are highly dynamic quantum processes. A fundamental question is whether coherence can be preserved in chemical reactions and then harnessed to generate entangled products. Here we investigated this question by studying the 2KRb → K₂ + Rb₂ reaction at 500 nK, focusing on the nuclear spin degrees of freedom. We prepared the initial nuclear spins in KRb in an entangled state by lowering the magnetic field to where the spin-spin interaction dominates and characterized the preserved coherence in nuclear spin wavefunction after the reaction. We observed an interference pattern that is consistent with full coherence at the end of the reaction, suggesting that entanglement prepared within the reactants could be redistributed through the atom-exchange process.

中文翻译：

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原子交换反应中的量子干涉


键断裂和形成的化学反应是高度动态的量子过程。一个基本问题是化学反应中是否可以保持相干性，然后利用它来产生纠缠的产物。在这里，我们通过研究 500 nK 下的 2KRb → K ₂ + Rb ₂ 反应来研究这个问题，重点关注核自旋自由度。我们通过将磁场降低到自旋-自旋相互作用占主导地位的位置来制备处于纠缠态的 KRb 中的初始核自旋，并表征了反应后核自旋波函数中保留的相干性。我们观察到与反应结束时完全相干一致的干涉图案，这表明反应物内形成的纠缠可以通过原子交换过程重新分布。