近日，德国耶拿大学的Andre Großardt及其研究团队取得一项新进展。经过不懈努力，他们通过半经典引力实现态交换。相关研究成果已于2025年1月13日在国际知名学术期刊《物理评论A》上发表。

该研究团队证明，半经典引力的哈密顿量导致的相干态演化，在理论和实验上都与相干态交换几乎无法区分。这项研究结果表明，仅根据引力能够交换一对相干态的能力，就对其性质得出确定性结论还为时过早。研究人员讨论了这些结果对提出的验证引力量子性质的实验测试的影响，并澄清了一些概念问题。

据悉，量子力学预测非局域现象的能力是其区别于经典理论的一个关键特性。最近有人提出，态交换就是这样一种效应，它根本无法由基本的经典引力场产生。其推理是，经典场的现象学仅限于局域操作和经典通信（LOCC），而态交换是一种非LOCC效应，因此，如果引力能产生这种现象，那么它就不可能是经典通道。

附：英文原文

Title: State swapping via semiclassical gravity

Author: Praveer K. Gollapudi^*, M. Kemal Döner^†, and Andre Großardt^‡

Issue&Volume: 2025-01-13

Abstract: The prediction of nonlocal phenomena is a key attribute of quantum mechanics that distinguishes it from classical theories. It was recently suggested that state swapping is one such effect that a fundamentally classical gravitational field cannot give rise to. The reasoning was that the phenomenology of classical fields is restricted to local operations and classical communication (LOCC), whereas swapping is a non-LOCC effect, so gravity must not be a classical channel if it can give rise to such a phenomenon. Here, we show that the Hamiltonian of semiclassical gravity results in an evolution of coherent states that is virtually indistinguishable from swapping them, both theoretically and experimentally. Our results indicate that drawing a definitive conclusion about the nature of gravity based solely on its ability to swap a pair of coherent states would be premature. We discuss the implications of these results regarding proposed experimental tests for the quantum nature of gravity and clarify some conceptual issues.

DOI: 10.1103/PhysRevA.111.012208

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.012208