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arXiv · 2507.00935

Light Manipulation via Tunable Collective Quantum States in Waveguide-Coupled Bragg and Anti-Bragg Superatoms

Zhengqi Niu·Wei Nie·Daqiang Bao·Xiaoliang He·Wanpeng Gao·Kuang Liu·I. -C. Hoi·Yu-xi Liu·Xiaoming Xie·Zhen Wang·Zhi-Rong Lin
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Abstract

A many-body quantum system which consists of collective quantum states, such as superradiant and subradiant states, behaves as a multi-level superatom in light-matter interaction. In this work, we experimentally study one-dimensional superatoms in waveguide quantum electrodynamics with a periodic array of superconducting artificial atoms. We engineer the periodic atomic array with two distinct nearest-neighbor spacings, i.e., $d$=$\lambda_0/2$ and $d$=$\lambda_0/4$, which correspond to Bragg and anti-Bragg scattering conditions, respectively. The system consists of eight atoms arranged to maintain these specific interatomic distances. By controlling atomic frequencies, we modify Bragg and anti-Bragg superatoms, resulting in distinctly different quantum optical phenomena, such as collectively induced transparency and a broad photonic bandgap. Moreover, due to strong waveguide-atom couplings in superconducting quantum circuits, efficient light manipulations are realized in small-size systems. Our work demonstrates tunable optical properties of Bragg and anti-Bragg superatoms, as well as their potential applications in quantum devices.

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Zhengqi Niu, Wei Nie, Daqiang Bao, Xiaoliang He, Wanpeng Gao, Kuang Liu, I. -C. Hoi, Yu-xi Liu, Xiaoming Xie, Zhen Wang, Zhi-Rong Lin. 2025-07-01. Light Manipulation via Tunable Collective Quantum States in Waveguide-Coupled Bragg and Anti-Bragg Superatoms. https://arxiv.org/abs/2507.00935

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