Origin of the noise in the high-Tcsuperconducting YBa2Cu3O7-δthin films

Abstract

In the mixed state of high-T c superconductors, the magnetic flux can penetrate the superconducting state in the form of vortices. Moving vortices create resistance, so they must be pinned to permit dissipationless current flow. This is particularly important issue for high-transition-temperature superconductors, in which the vortices move very easily. We studied the behavior of the characteristic noise of high-T c superconductors near the transition conductor-superconductor region in YBa 2 CU 3 O 7-δ thin films as a function of the temperature and of the applied magnetic field. Our results show that when the temperature increases near the superconducting transition region, the amplitude of the voltage noise increases. And this amplitude depends strongly on the electrical current crossing the sample.