Experimental Study of an Elementary Cryogenic Microwave Quantum Network*

Scaling up quantum computers can follow two routes in parallel: increasing the computing power of single processors, and connecting multiple processors into quantum networks using chip-to-chip deterministic quantum protocols. In both cases, modularity is a key concept. Similarly, the space available at cryogenic temperatures and cooling power needed for superconducting quantum processors can be scaled-up in a modular way by connecting dilution refrigerators into cryogenic networks. In this talk, we present an experimental study of essential elements of a cryogenic quantum network. Based on a modular design, we realize a proof-of-concept, cryogenic link between two network nodes. We thoroughly analyze the thermal properties of the link elements and extrapolate to distance scales which appear attainable in the presented approach. We also report progress toward transfering quantum information between nodes of the network.