PHOTON-INDUCED VORTEX-ANTIVORTEX PAIR CREATION IN SUPERCONDUCTING FILMS

We have used a DC SQUID (superconducting quantum interference device) gradiometer to study vortex-antivortex pair creation in both two-dimen sional superconducting films and Josephson junction arrays in the pres ence of 850 nm light irradiation. Specifically the experiments aim to distinguish between the formation of vortex-antivortex pairs by single -photon absorption and by thermal activation. A major objective for th is experiment is to investigate the possibility of using vortex-antivo rtex pair creation and subsequent detection as the basis for a photon detector.