河南师范大学Chang-shui Yu团队近日研究了超强光-物质耦合系统中的量子纠缠和爱因斯坦-波多尔斯基-罗森操纵。这一研究成果发表在2025年5月19日出版的《物理评论A》上。

这项工作提出了一种基于量子Hopfield模型的高斯测量的工程量子纠缠和爱因斯坦-波多尔斯基-罗森（EPR）操纵方案，该模型包含一个共同的热库。课题组首先研究基态中的量子关联，特别是量子纠缠和EPR操纵。这些量子关联主要源于弱耦合和正常强耦合机制中的压缩相互作用。 

随着耦合强度的增加，特别是在进入超强耦合状态时，压缩和混合模相互作用的共同作用产生了相关性。重要的是，这种情况能够实现双向EPR转向。此外，较低的光频率增强了量子纠缠和EPR转向。进一步地，在考虑热效应时，超强耦合和深强耦合机制与较低的光学频率相结合，可以改善纠缠。 

共振情况下的单向EPR转向可以在超强耦合和深强耦合状态下得到有效控制，这些状态源于反磁项引起的子系统和储层耦合的不对称性。此外，还可以为非共振情况生产单向EPR转向。在这种情况下，子系统和储层的不对称性源于非共振频率和反磁性项的共同作用。该发现有可能激发对利用光物质纠缠和EPR操纵的量子信息处理的进一步研究。

附：英文原文

Title: Quantum entanglement and Einstein-Podolsky-Rosen steering in ultrastrongly light-matter-coupled systems

Author: Yu-qiang Liu, Shan Sun, Yi-jia Yang, Zheng Liu, Xingdong Zhao, Zunlue Zhu, Wuming Liu, Chang-shui Yu

Issue&Volume: 2025/05/19

Abstract: This work presents a scheme for engineering quantum entanglement and Einstein-Podolsky-Rosen (EPR) steering with Gaussian measurements based on the quantum Hopfield model that incorporates a common thermal reservoir. We begin by examining quantum correlations, specifically quantum entanglement and EPR steering, in the ground state. These quantum correlations primarily stem from squeezing interactions in weak-coupling and normal strong-coupling regimes. As the coupling strength increases, especially upon entering the ultrastrong-coupling regime, the correlations emerge from the combined effect of squeezing and mix-mode interactions. Importantly, this scenario enables the realization of two-way EPR steering. Moreover, lower optical frequencies enhance both quantum entanglement and EPR steering. Further, when considering thermal effects, the ultrastrong-coupling and deep strong-coupling regimes, paired with lower optical frequencies, lead to improved entanglement. The one-way EPR steering for the resonant case can be effectively controlled in the ultrastrong-coupling and deep strong-coupling regimes which originate from the asymmetry of the subsystem and reservoir coupling induced by the diamagnetic term. Additionally, one-way EPR steering can also be produced for the nonresonant case. In this case, the asymmetry of the subsystem and reservoir originates from the combined effect of nonresonant frequencies and the diamagnetic term. Our findings have the potential to inspire further research into quantum information processing that leverages light-matter entanglement and EPR steering.

DOI: 10.1103/PhysRevA.111.052437

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.052437