Quantum flux parametron
Invented by Eiichi Goto at the University of Tokyo, the Quantum Flux Parametron (QFP) is an improvement over his earlier parametron based digital logic technology. Unlike its predecessor, QFP uses superconducting Josephson junctions on integrated circuits to improve speed and energy efficiency enormously. In some applications, the complexity of the cryogenic cooling system required is negligable compared to the potential speed gains. While his design makes use of quantum principles, it is not a quantum computer technology, gaining speed only through higher clock speeds. Apart from the advantage over traditional circuit design is that parametrons can be operated with zero energy loss (no local increase in entropy), making reversible computing possible. Low energy use and heat generation is critical in supercomputer design, where thermal load per unit volume is has become one of the main limiting factors.
A related technology is the Rapid Single Flux Quantum digital logic.