Dynamic mixed state in micron-size bridges based on Bi2Sr2CaCu2Ox whiskers

Measurements of the current-voltage characteristics of micron-size bridges made of Bi₂Sr₂CaCu₂O_x single-crystal whiskers are carried out. It is found that, at temperatures below the superconducting transition temperature, the current-voltage characteristics exhibit quasi-periodic voltage jumps with segments of constant differential resistance whose value is proportional to the jump number. For the narrowest bridges (0.5–1 ¼m), up to ten voltage jumps are observed. The result of the experiment is explained by the formation of vortex lines under the current effect.