High-Density Flexible Cables for Superconducting Electronics

To address DARPA’s need to create a new type of high-density data cable for superconducting electronics applications which has high density, low attenuation, low crosstalk, and low heat load, Bleximo Corp proposes to develop and test, at cryogenic temperatures, cables for a full-stack robust low-loss, low thermal conductance, modular, scalable input/output RF cable on flexible substrates, including: a.) Optimization of properties of cables (insertion loss and heat load) for each temperature interval, b.) Development of matched interconnects with SMA and G3PO connectors to interface with COTS components, primarily at room and 10 mK temperatures, c.) Development of matched interconnects with printed circuit boards for use with surface-mounted filtering and signal routing components as well as quantum processors and other superconducting circuits, d.) Development of integrated attenuators for control and readout lines, e.) Optimization of the lines for noise temperature balance at the mixing chamber of a dilution refrigerator and the amount of dissipated heat, f.) Ensure design compatibility with existing commercial DR systems, g.) Study alternative manufacturing methods, including 3D printing, and h.) Manufacture and measure properties of 15 cm long 3-channel ribbon cables at millikelvin temperatures , including RF signal transmission properties and cross-talk between channels.  Our preliminary simulations indicate that both the target primary and secondary metrics required in this Program can be achieved in this design with appropriate selection of metallic materials.