CRITICAL CURRENTS IN SUBMICRON YBa2Cu3O7 LINES

Lines in YBa2Cu3O7 with widths down to 200 nanometers and properties comparable with the original film, have been defined using electron beam lithography and plasma etching. One predicted property of lines smaller than the magnetic penetration depth is an increase in the critical current density due to pinning of the vortices at the edge of the sample. There have been several reports of experimental observation of edge pinning in narrow YBa2Cu3O7 lines. We present systematic measurements of narrow lines that should be far into the edge pinning regime. Nevertheless no increase of critical current density is observed in the smallest lines.