Extending Cryogenic Microwave Quantum Networks*

A promising route for scaling up quantum computers based on superconducting circuit technology is to connect multiple processors to each other using chip-to-chip deterministic quantum protocols [1,2,3,4,5]. The protocols are used either between chips housed in a single cryogenic system or spatially separated ones connected by a cryogenic microwave quantum network.
We have realized such a modular cryogenic quantum network connecting two dilution refrigerators separated by 5 meters [6] and plan to extend it to 30 meters. In this talk, we present the design and concept of the cryogenic link we have developed. We analyse its thermal properties and review its electrical characteristics. We further discuss the modularity and distance scales attainable with our system.

[1] C. Dickel et al., PRB 97, 064508 (2018)
[2] C. Axline et al., Nature Physics 14, 705 (2018)
[3] P. Campagne-Ibarcq et al., PRL 120, 200501 (2018)
[4] P. Kurpiers et al., Nature 558, 264 (2018)
[5] N. Leung et al., npj Quantum Information 5, 18 (2019)
[6] P. Magnard et al., arXiv:2008.01642 (2020)