Transport properties of small-sized intrinsic Josephson junctions in Bi2Sr2CaCu2Oy

Transport properties of small-sized intrinsic Josephson junctions in Bi2Sr2CaCu2Oy have been systematically investigated with respect to both junction size and temperature. Using electron-beam lithography and Ar ion milling, we have successfully fabricated mesas with lateral dimensions ranging from sub-mum(2) to several tens mum(2) on the same crystal. Typical multiple resistive branches with hysteresis and well defined gap structures were observed in the I-V characteristics of the mesas at 4.2 K. In addition, we observed the suppression of the critical current densities as lateral dimensions of the mesa decrease down to less than 1 mum(2). We interpret the decrease in J(c) of submicron junctions in terms of the contribution of the Coulomb blockade effect. (C) 2001 Elsevier Science B.V. All rights reserved.