On Possibility of Using High-Tc Ceramic-Superconductor as Junction-less   Transistor towards Nano-miniaturization
  High-Tc Type-II ceramic-superconductor at temperature T < Tc, under presence of magnetic-field B becomes non-superconducting if B exceeds a critical value Bc2. Thus at T < Tc, by application/absence of critical magnetic- field as a controlling device, these non-superconducting/superconductor states can be achieved for current-flow to two corresponding states of block/pass or off/on or 0/1. Thus it appears that there is a possibility of a new breed of transistors purely with high-Tc Type-II ceramic-superconductor; compact and without junctions & complexities. The proposed ceramic-superconductor-transistor (CST) seems in-principle to work well for switching purpose, but its use could also be extended for other electronic/computer devices too. The CST, being junction-less thus diffusion-less, could possibly be packed more closely (at nano-level) than the semi-conductor devices which has a limitation due to diffusion-layer-overlapping. A similar superconductor-device named Cryotron was invented at MIT half-a-century ago, but could not survive against semiconductor. CST is a rebirth of cryotron in different disguise & in new perspective. 
R.C. Gupta, Ruchi Gupta and Sanjay Gupta