ELECTRIC-FIELD EFFECT ON EPITAXIAL YBA2CU3O7-X THIN-FILMS

By applying a strong electric field perpendicular to the surface of an ultrathin, highly uniform epitaxial YBa2Cu3O7-x film, the critical cu rrent was depressed and enhanced over 20% at temperatures close to T(c ), and 5% at lower temperatures. Careful analysis of the electric fiel d dependent I-V characteristics and Arrhenius plots indicate that the electric field effect can be interpreted as a change in the pinning po tential and/or the vortex-antivortex interaction potential in the Kost erlitz-Thouless regime, as a result of a change in the carrier density in the superconductor.