Magnesium Diboride Flexible Flat Cables for Cryogenic Electronics

Abstract: Magnesium diboride (MgB2) thin films are a potential alternative to low-temperature superconductors (LTS) due to a higher critical temperature (Tc) of approximately 39 K. The reactive evaporation deposition technique also affords relatively simple growth of MgB2 films on flexible substrates compared to high-temperature superconductors (HTS). We have designed and fabricated a cable architecture consisting of MgB2 traces on flexible yttria-stabilized zirconia (YSZ) compatible with commercially available connectors or direct wirebonds. Key performance metrics such as critical current density (Jc) and Tc are measured and compared. We discuss thermal conductivity and passivation schemes for these cables.