Connecting Superconducting Circuits Over a Kilometer of Optical Fiber

In a key step toward large-scale quantum computing, C2QA researchers transferred quantum signals between dilution refrigerators via fiber

May 22, 2026

Illustration of a one-kilometer-long photonic link connecting superconducting circuits in two diluti enlarge

Illustration of a one-kilometer-long photonic link connecting superconducting circuits in two dilution refrigerators.

Scientific Achievement

C2QA researchers demonstrated coherent transfer of quantum signals between superconducting circuits in dilution refrigerators connected by a one-kilometer optical fiber, achieving an 80-decibel improvement in transmission efficiency over conventional optical modulators.

Significance and Impact

Scaling superconducting quantum processors to the millions of qubits needed for practical computation requires linking multiple cryostats, a challenge that conventional microwave wiring cannot meet. This work establishes a practical blueprint for large-scale superconducting quantum networks via scalable, low-loss photonic links.

Research Details

  • Demonstrated coherent signal transfer over one kilometer of telecom optical fiber between two dilution refrigerators
  • Developed a new transducer design with precise frequency matching between two independent devices
  • Achieved >0.1% on-chip transduction efficiency

Collaborating Institutions

  • Yale University

Publication

Zhou Y, Wu Y. Li, CZ, Shen, M., Yang, L, Xie J, Tang, H., “A 1-km photonic link connecting superconducting circuits in two dilution refrigerators”, Nature Photonics  (2026)
https://doi.org/10.1038/s41566-026-01866-7

Acknowledgements 

This research is funded by the Co-design Center for Quantum Advantage under DE-SC0012704. Support was also provided to HXT by the NSF’s National Quantum Virtual Laboratory program under 2410725, to Y.Z. from Yale Quantum Institute fellowship (Y.Z.). We would like to thank X. Han, S. Wang and W. Fu for refrigeration hardware installation, and Y. Sun, L. McCabe, K. Woods, Y. Shin, M. Rooks and S. Sohn for their assistance provided in the device fabrication. The fabrication of the devices was done at the Yale School of Engineering & Applied Science (SEAS) Cleanroom and the Yale Institute for Nanoscience and Quantum Engineering (YINQE). The TWPA used in this experiment is provided by IARPA and MIT Lincoln Laboratory.

2026-22966  |  INT/EXT  |  Newsroom