Superconductors as very high-speed system-level interconnects

The anticipated propagation characteristics at 77 K of superconducting transmission lines using the new high critical temperature superconductor Ba-Y-Cu-O are calculated and compared with propagation characteristics at 77 K and 300 K of normal aluminum interconnects. The major advantages of superconducting interconnections are: 1) packing density can be increased without incurring the penalties of high loss associated with very dense interconnects of normally conducting lines; 2) propagation time can be greatly reduced; and 3) dispersion is virtually nonexistent for frequencies up to several tens of gigahertz. The peak RF magnetic field (i.e., the linear surface critical current density) and the penetration depth are important material parameters in the operation of superconducting transmission lines.