Easy vortex motion in an artificial channel of YBa₂Cu ₃O_7-δ superconducting films

Quasi-Josephson effect produced by a coherent vortex motion in the horizontal part of the laser-performed n-shaped channel of a YBa ₂Cu₃O_7-δ superconducting bridge was investigated by means of electric transport measurements. We observed that in our structures, in a limited range of temperatures and bias currents, the vortices were confined in the channel only and moved coherently with the velocity of 3 × 10⁴ m/s. The corresponding current-voltage characteristics of the bridge exhibited Josephson-like voltage steps with the amplitude dependent on temperature, but independent of the bias current.