Circuit Quantum Acoustodynamics in a Scalable Phononic Integrated Circuit Architecture

TL;DR

This paper introduces a scalable quantum acoustic architecture integrating superconducting qubits with phononic circuits, enabling coherent phonon control and paving the way for phonon-based quantum computing.

Contribution

It presents a novel scalable architecture for circuit quantum acoustodynamics by integrating superconducting qubits with suspension-free phononic integrated circuits.

Findings

Achieved coherent coupling between transmon qubits and phononic cavities.

Enhanced phonon emission with a Purcell factor of ~19.

Demonstrated integration of Fabry-Perot and microring phononic cavities.

Abstract

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.