Single-Crystal Switching Gates Fabricated Using Cuprate Superconductors

We propose new switching gates based on layered structures of high-T c superconductive single crystals. The operation principle of the proposed gate is similar to that of Josephson junction switches but its size is smaller and its speed is faster than those of Josephson junctions. The proposed switching gates consist of a gate current pass parallel to the c-axis of the single crystal. The gate current is controlled by a magnetic flux induced by input current. The area of the gate is less than 1 µ m2. The minimum switching time τ s is estimated as \cong10-13 s. The gate can be used as a memory cell and a flux flow amplifier. As the proposed gate uses a single crystal the noise figure should be low if the crystal used is of high quality.