Comment superconducting chips (Score 1) 195
No, superconducting chip designs are possible, if you're sufficiently clever. IBM and other groups spent lots of money in the 70s trying to use Josephson junctions in a way analogous to transistors, so that the presence of a voltage on a line was a '1' and lack of a voltage was '0'. This was a dead end.
A more recent development has been to set aside these preconceptions and use the unique properties of superconductors. If you have a ring of superconductor, you can trap a quantum of magnetic flux in it- this corresponds to a bit of current flowing eternally around the ring. If a Josephson junction is part of the ring, it can, by changing state, release the flux quantum, creating a voltage pulse. Google for 'RSFQ' and you'll find lots more information.
A more recent development has been to set aside these preconceptions and use the unique properties of superconductors. If you have a ring of superconductor, you can trap a quantum of magnetic flux in it- this corresponds to a bit of current flowing eternally around the ring. If a Josephson junction is part of the ring, it can, by changing state, release the flux quantum, creating a voltage pulse. Google for 'RSFQ' and you'll find lots more information.
