近日，东北师范大学的衣学喜及其研究小组与延边大学的王洪福合作并取得一项新进展。经过不懈努力，他们实现可调谐非互易纠缠和双光子驱动诱导单向导引的操纵。相关研究成果已于2024年6月17日在国际知名学术期刊《物理评论A》上发表。

该研究团队深入探索了一个全光学系统，该系统由两个回音廊模式微环谐振器以及两个相邻的光波导组成。该系统的独特之处在于，它能够同时激发两个谐振腔中的顺时针和逆时针模式，仅通过来自不同方向的泵浦场即可实现。当激发光子的传播方向与双光子驱动激发光子的传播方向相同时，系统能够高效、稳定地产生满足相位匹配条件的非互易量子纠缠，和单向爱因斯坦-波多斯基-罗森（EPR）导引。

这项工作表明，只有当系统被来自唯一端口的泵浦场驱动时，量子关联性才得以制备，这完全归因于系统的非线性特性。此外，他们还发现，当两种光模式的频率失谐相反时，量子纠缠和单向EPR导引的强度会达到最大值。更值得一提的是，提高双光子驱动强度和耦合强度能显著增强这两种量子效应。

这项研究提供了一个高度可操纵的平台，为基于宏观纠缠态的单向量子计算和量子通信提供了希望。

附：英文原文

Title: Manipulation of tunable nonreciprocal entanglement and one-way steering induced by two-photon driving

Author: Si-Yu Guan, Hong-Fu Wang, Xuexi Yi

Issue&Volume: 2024/06/17

Abstract: We consider an all-optical system consisting of two whispering-gallery-mode microring resonators and two adjacent optical waveguides. Pumping fields from different directions can simultaneously excite both clockwise and counterclockwise modes in the two resonators. When the propagation direction of the excited photons aligns with the propagation direction of the photons excited by two-photon driving, satisfying the phase-matching conditions, stable nonreciprocal quantum entanglement and one-way Einstein-Podolsky-Rosen (EPR) steering can be effectively generated. This work demonstrates that quantum correlations can only be prepared when the system is driven by a pumping field from the unique port, a condition induced by the nonlinearity of the system. Furthermore, we show that the maximum values of quantum entanglement and one-way EPR steering can be achieved when the frequency detunings of the two optical modes are opposite, and higher two-photon driving strength and coupling strength significantly enhance quantum entanglement and one-way EPR steering. Our study provides a highly manipulable platform, offering promise for one-way quantum computing and quantum communication based on macroscopic entangled states.

DOI: 10.1103/PhysRevA.109.062423

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.062423