Interface between cryogenic computational hardware and room temperature computational hardware

An interface between cryogenic computational hardware and room temperature computational hardware, the interface comprising:

• a plurality of discrete stages, including a first stage at room temperature and a last stage at a cryogenic temperature, each successive stage being configured for operation at a corresponding refrigeration temperature that is lower than the refrigeration temperature of each preceding stage and including a set of planar transmission lines, the transmission lines of any given stage other than the first stage being proximally coupled to and contiguous with the transmission lines of an immediately preceding stage, the transmission lines of the first stage being proximally coupled to the room temperature computational hardware and the transmission lines of the last stage being proximally coupled to the cryogenic computational hardware, each stage having shielding configured to block electromagnetic radiation external to such stage;
• wherein the transmission lines of any stage other than the first stage are implemented as a stripline passing through a feedthrough aperture in a cap and barrier interface, the feedthrough aperture in the cap and barrier interface being defined by a clamping face of a cap and a surface of a barrier, wherein the cap is configured to squeeze the stripline against the barrier and shaped so as to provide a light seal preventing transmission of radiation between adjacent stages along the cap and barrier interface and the stripline.