| 摘要 |
<PICT:1023519/C6-C7/1> A cryogenic device comprises a thin striated discontinuous superconductive film in which the distances between the islands in one direction is small enough to permit tunnelling; separation between islands in the direction normal to the first, is greater. Fig. 7 shows a device comprising a layer 4 of lines of isolated islands of superconductor material deposited on a substrate 1 between electrodes 2 and 3. The island structure of the layer, which may be 100-5000</>r thick, is produced by evaporation of the superconductor material at a high angle of incidence on to the substrate; a pre-coating of a nucleating material in the desired pattern may be used to assist island formation or deposition may be effected through a slotted mask. Alternatively, the surface of the substrate may be machined to form parallel lines, such as by subjection to an electron beam. The superconductor material may be Al, Pb, Ni, Ta, Sn, Ti or Va. The terminals may be of superconductor material, a superconducting ground plane may be provided, and the layer may be protected by a layer of silicon monoxide. The substrate temperature is maintained substantially at the melting temperature of the coating material. |
