近日，湖南师范大学的廖洁桥及其研究小组取得一项新进展。经过不懈努力，他们研究了波导- QED系统中两巨型原子纠缠的产生过程。相关成果已于2023年8月28日在国际知名学术期刊《物理评论A》上发表。
该研究团队研究了在一维波导上耦合的两个巨型原子之间的量子纠缠的产生过程。由于每个巨型原子在两个独立的耦合点与波导相互作用，因此在两原子波导系统中存在三种不同的耦合结构：分离耦合、编织耦合和嵌套耦合。在单耦合点的Wigner-Weisskopf框架内，研究人员得到了控制两个巨型原子演化的量子主方程。对于每种耦合构型，他们研究了两个巨型原子的纠缠动力学，包括两种不同原子初始态：单激发态和双激发态的情况。
该研究的结果表明，所产生的纠缠依赖于耦合构型、相移和原子初始态。对于单激发初始态，由于暗态的出现，这三种耦合都存在稳态纠缠。对于双激发初始态，通过调整相移可以观察到纠缠的突然产生。特别是，嵌套耦合的最大纠缠比分离耦合和编织耦合的最大纠缠大约大一个数量级。
此外，他们还研究了原子频率失谐对纠缠产生的影响。本工作可用于基于巨型原子波导QED系统的量子网络中原子纠缠的产生和控制，在量子信息处理中具有广泛的应用前景。
附：英文原文
Title: Generation of two-giant-atom entanglement in waveguide-QED systems
Author: Xian-Li Yin, Jie-Qiao Liao
Issue&Volume: 2023/08/28
Abstract: We study the generation of quantum entanglement between two giant atoms coupled to a one-dimensional waveguide. Since each giant atom interacts with the waveguide at two separate coupling points, there exist three different coupling configurations in the two-atom waveguide system: separated, braided, and nested couplings. Within the Wigner-Weisskopf framework for single coupling points, the quantum master equations governing the evolution of the two giant atoms are obtained. For each coupling configuration, the entanglement dynamics of the two giant atoms is studied, including the cases of two different atomic initial states: single- and double-excitation states. It is shown that the generated entanglement depends on the coupling configuration, phase shift, and atomic initial state. For the single-excitation initial state, there exists steady-state entanglement for these three couplings due to the appearance of the dark state. For the double-excitation initial state, an entanglement sudden birth is observed via adjusting the phase shift. In particular, the maximal entanglement for the nested coupling is about one order of magnitude larger than those of separate and braided couplings. In addition, the influence of the atomic frequency detuning on the entanglement generation is studied. This work can be utilized for the generation and control of atomic entanglement in quantum networks based on giant-atom waveguide-QED systems, which have wide potential applications in quantum information processing.
DOI: 10.1103/PhysRevA.108.023728
Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.108.023728
来源：科学网 小柯机器人