Previous demonstrations of quantum acoustic systems have been limited to isolated devices, with limited capability to route phonons and interconnect multi-port acoustic elements for further extension. Here, we demonstrate a scalable architecture for circuit quantum acoustodynamics (cQAD) by integrating superconducting qubits with suspension-free phononic integrated circuits (PnICs). Coherent coupling between tunable transmon qubits and waveguide-integrated phononic cavities, including Fabry-Perot cavities via monolithic integration and microring cavities via flip-chip assembly, has been achieved, producing a pronounced enhancement of phonon emission with a Purcell factor of ~19. These devices represent elementary building blocks for scalable phononic circuits, establishing the foundation for phonon-based quantum information processors and the testbed for novel quantum acoustic phenomena.
@article{arxiv.2512.04953,
title = {Circuit Quantum Acoustodynamics in a Scalable Phononic Integrated Circuit Architecture},
author = {Weiting Wang and Lintao Xiao and Bo Zhang and Yu Zeng and Ziyue Hua and Chuanlong Ma and Hongwei Huang and Yifang Xu and Jia-Qi Wang and Guangming Xue and Haifeng Yu and Xin-Biao Xu and Chang-Ling Zou and Luyan Sun},
journal= {arXiv preprint arXiv:2512.04953},
year = {2025}
}