Electrical Сharacteristics of Long Josephson Junctions Based on Tungsten Nanorods as Weak Links: Effect of Random Critical-Current Distributions

The numerical model of long Josephson junctions with Gaussian spread of critical currents has been developed. The model allowed calculating the IV-characteristics and power of emission of long junctions. Zero-field steps in IV-characteristics in the hysteretic region were found. When the spread of critical currents was comparable with the value of the averaged critical current, particularities corresponded to zero-field steps were found in the derivative of the IV-characteristic far above the hysteretic region. Results were qualitatively explained in ranges of the existing theory of zero-field steps in IV-curves of Josephson junctions with random distributions of critical currents. The model was applied for the approximation of particularities in the derivative of the earlier measured IV-curve of the heterostructure consisted of two superconducting electrodes made up of molybdenum-rhenium alloy and a hybrid semiconductor tunnel barrier with a nanosized silicon layer which contained tungsten nanoclusters [the MoRe-Si(W)-MoRe heterostructure]. The model described adequately positions of particularities in the derivative of the IV-characteristic in the wide range of voltages.