Oscillations in the current-voltage characteristics of inter-grain Y-Ba-Cu-O junctions

Abstract

I-V curves of bulk Y-Ba-Cu-O samples show Josephson tunnelling characteristics comprising finite pair current and quasi-particle tunnelling regions. The authors report here the first observations of oscillatory structures superposed on these curves under impressed microwave or small DC magnetic fields. A possible explanation of these oscillations is believed to be tunnelling of individual electrons charging and discharging the capacitance of a large number of inter-grain Josephson junctions.