Fig. 2: Layered structure of the cryogenic link.
From: Cryogenic microwave link for quantum local area networks
a Cryogenic link schematics consisting of two dry dilution refrigerators (Alice and Bob) spatially separated by 6.6 m. Each stage of the cryogenic link is labeled with its typical steady-state temperature. The innermost stage of the cryogenic link contains three superconducting NbTi coaxial cables, which allow for distribution of microwave quantum signals. A third, intermediate, cryostat without a dilution unit (Eve) is used to support the cooling of the two outermost radiation shields (at temperatures of 50 K and 3.5 K, respectively) via an additional pulse tube cooler. b Base temperature profile along the superconducting NbTi cables and MC tube. Stars correspond to measured temperatures at the center of the cryogenic link, for which positions are indicated in panel (a). Solid lines are the result of a heat equation simulation, which takes into account radiation incident on the cables and MC tube, and conductive heat transfer between the cables and MC tube. As boundary conditions, we use the measured temperatures at the MC stages of Alice and Bob.
