Optical readout of a superconducting qubit using a scalable piezo-optomechanical transducer

• Main Authors: van Thiel, T. C, Weaver, M. J, Berto, F, Duivestein, P, Lemang, M, Schuurman, K. L, Žemlička, M, Hijazi, F, Bernasconi, A. C, Ferrer, C, Lachman, E, Field, M, Mohan, Y, de Vries, F. K, Bultink, C. C, van Oven, J, Mutus, J. Y, Stockill, R, Gröblacher, S
• Format: Journal Article
• Language: English
• Published: 09.10.2023
• Subjects: Physics - Quantum Physics
• DOI: 10.48550/arxiv.2310.06026

Superconducting quantum processors have made significant progress in size and computing potential. As a result, the practical cryogenic limitations of operating large numbers of superconducting qubits are becoming a bottleneck for further scaling. Due to the low thermal conductivity and the dense optical multiplexing capacity of telecommunications fiber, converting qubit signal processing to the optical domain using microwave-to-optics transduction would significantly relax the strain on cryogenic space and thermal budgets. Here, we demonstrate optical readout through an optical fiber of a superconducting transmon qubit connected via a coaxial cable to a fully integrated piezo-optomechanical transducer. Using a demolition readout technique, we achieve a single shot readout fidelity of 81%. Due to the small footprint (<0.15mm$^2$) and the modular fiber-based architecture, this device platform has the potential to scale towards use with thousands of qubits. Our results illustrate the potential of piezo-optomechanical transduction for low-dissipation operation of large quantum processors.