标题： 手性在原子二聚体波导-量子电动力学系统中引起的非互易路由 显示英文标题

标题： Nonreciprocal routing induced by chirality in an atom-dimer waveguide-QED system

摘要： 量子路由器的实现是量子信息科学中一项重要且迫切的任务，因为量子路由器是量子网络的重要组成部分。 在这里，我们提出了一种在波导-腔量子电动力学系统中实现单光子路由器的方案，该系统由两个耦合的两能级原子耦合到两个波导上，形成一个四端口量子器件。 我们使用实空间方法得到了单光子散射振幅的精确解析表达式。 通过考虑光子在两个耦合点之间的传播时间或不考虑，我们分别研究了系统在马尔可夫和非马尔可夫 regimes 下的工作情况。 此外，我们引入了手性耦合，这打破了波导模型的对称性，以操控单光子的传输。 我们发现，当系统在非马尔可夫 regime 下工作时，可以通过调整不对称系数按需传输单光子。 更有趣的是，该器件中的完全单光子路由不需要理想的手性耦合，放宽了光子传输条件。 这项工作将激发在波导-腔量子电动力学平台上关于非互易和手性量子器件的研究。 显示英文摘要

摘要： The implementation of quantum routers is an important and desired task in quantum information science, since quantum routers are important components of quantum networks. Here, we propose a scheme for implementing single-photon routers in a waveguide-QED system, which consists of two coupled two-level atoms coupled to two waveguides to form a four-port quantum device. We obtain the exact analytical expressions of the single-photon scattering amplitudes using the real-space method. By taking the propagating time of photons between two coupling points into account or not, we consider the system working in the Markovian and non-Markovian regimes, respectively. In addition, we introduce the chiral coupling, which breaks the symmetry of the waveguide model, to manipulate the transmission of single photons. We find that when the system works in the non-Markovian regime, the single photon can be transmitted on demand by adjusting the asymmetry coefficient. More interestingly, the complete single-photon routing in this device does not require an ideal chiral coupling, loosening the photon transport conditions. This work will motivate the studies concerning the nonreciprocal and chiral quantum devices in the waveguide-QED platform.