Work

Superfluid-Cooled Transmon Qubits under Optical Excitation

Year: 2025

Type: article

Abstract: Microwave-to-optical quantum state transfer enables the interconnection of remote superconducting quantum processors via optical-fiber links. Achieving high conversion efficiency necessitates an intense optical pump, yet direct optical exposure of superconducting circuits often degrades their performance. Efficient and fast thermalization of superconducting qubits is therefore essential. To achieve this, we immerse a laser-illuminated transmon qubit in superfluid helium-4 and investigate its behavior. We observe that the qubit recovers significantly faster in superfluid helium than in vacuum, with an improvement in power handling by over 10 dB. This enhanced cooling capacity supports higher optical pump powers, shortening recovery times after high-power optical pulses. These findings open a promising pathway for future efficient implementation of microwave-to-optical quantum transduction devices.

Source: PRX Quantum

DOI: 10.1103/q99s-lrnv

Authors: Chunzhen Li, Yufeng Wu, Manuel C. C. Pace, Matthew D. LaHaye, Michael Senatore, Hong X. Tang

Institutions: Yale University, U.S. Air Force Research Laboratory Information Directorate

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,450

Funders: U.S. Department of Energy, Multidisciplinary University Research Initiative, Air Force Office of Scientific Research