Observation of Inelastic Meson Scattering in a Floquet System using a Digital Quantum Simulator

Ziting Wang; Zi-Yong Ge; Yun-Hao Shi; Zheng-An Wang; Si-Yun Zhou; Hao Li; Kui Zhao; Yue-Shan Xu; Wei-Guo Ma; Hao-Tian Liu; Cai-Ping Fang; Jia-Cheng Song; Tian-Ming Li; Jia-Chi Zhang; Yu Liu; Cheng-Lin Deng; Guangming Xue; Haifeng Yu; Kai Xu; Kaixuan Huang; Franco Nori; Heng Fan

arXiv · 2508.20759

Observation of Inelastic Meson Scattering in a Floquet System using a Digital Quantum Simulator

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Abstract

Lattice gauge theories provide a non-perturbative framework for understanding confinement and hadronic physics, but their real-time dynamics remain challenging for classical computations. However, quantum simulators offer a promising alternative for exploring such dynamics beyond classical capabilities. Here, we experimentally investigate meson scattering using a superconducting quantum processor. Employing a digital protocol, we realize a Floquet spin chain equivalent to a one-dimensional Floquet $\mathbb{Z}_2$ lattice gauge theory. We observe Bloch oscillations of single kinks and strong binding between adjacent kinks, signaling confinement and the formation of stable mesons in this Floquet system. Using full-system joint readout, we resolve meson populations by string length, enabling identification of meson scattering channels. Our results reveal the fragmentation of a long-string meson into multiple short-string mesons, which is also an experimental signature of string breaking. Moreover, we directly observe inelastic meson scattering, where two short-string mesons can merge into a longer one. Our results pave the way for studying interacting gauge particles and composite excitations on digital quantum simulators.

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Ziting Wang, Zi-Yong Ge, Yun-Hao Shi, Zheng-An Wang, Si-Yun Zhou, Hao Li, Kui Zhao, Yue-Shan Xu, Wei-Guo Ma, Hao-Tian Liu, Cai-Ping Fang, Jia-Cheng Song, Tian-Ming Li, Jia-Chi Zhang, Yu Liu, Cheng-Lin Deng, Guangming Xue, Haifeng Yu, Kai Xu, Kaixuan Huang, Franco Nori, Heng Fan. 2025-08-28. Observation of Inelastic Meson Scattering in a Floquet System using a Digital Quantum Simulator. https://arxiv.org/abs/2508.20759

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