Exploring the properties and applications of topological quantum states is essential to better understand topological matter. Here, we theoretically study a quasi-one-dimensional topological atom array. In the low-energy regime, the atom array is equivalent to a topological superatom. Driving the superatom in a cavity, we study the interaction between light and topological quantum states. We find that the edge states exhibit topology-protected quantum coherence, which can be characterized from the photon transmission. This quantum coherence helps us to find a superradiance-subradiance transition, and we also study its finite-size scaling behavior. The superradiance-subradiance transition also exists in symmetry-breaking systems. More importantly, it is shown that the quantum coherence of the subradiant edge state is robust to random noises, allowing the superatom to work as a topologically protected quantum memory. We suggest a relevant experiment with three-dimensional circuit QED. Our study may have applications in quantum computation and quantum optics based on topological edge states.

中文翻译：

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超级原子中的拓扑保护量子相干。

探索拓扑量子态的性质和应用对于更好地理解拓扑物质至关重要。在这里，我们从理论上研究准一维拓扑原子阵列。在低能状态下，原子阵列等效于拓扑超原子。在腔中驱动超原子，我们研究光与拓扑量子态之间的相互作用。我们发现边缘状态表现出拓扑保护的量子相干性，这可以通过光子传输来表征。这种量子相干性帮助我们找到了超辐射度-亚辐射度的跃迁，并且我们还研究了其有限尺寸的缩放行为。超辐射-次辐射过渡也存在于对称破坏系统中。更重要的是，表明亚辐射边缘状态的量子相干性对随机噪声具有鲁棒性，允许超原子充当受拓扑保护的量子存储器。我们建议使用三维电路QED进行相关实验。我们的研究可能会在基于拓扑边缘状态的量子计算和量子光学中应用。