RANDOM TELEGRAPH VOLTAGES IN HIGH-T-C THIN-FILMS AT ZERO MAGNETIC-FIELD

New class of random telegraph voltage noise signals has been observed in zero field cooled BiSrCaCuO films at currents several times exceedi ng the critical current of the sample. The amplitude of the telegraph signal scales linearly with current bias. Average lifetimes demonstrat e distinct behavior in up and down voltage states indicating that the energy barrier associated with the down state decreases linearly with increasing current while that of the up state is nonlinear and reaches a maximum at a symmetric telegraph signal.