TIME DOMAIN SIMULATION OF SHAPIRO STEPS IN JOSEPHSON JUNCTIONS.

Using the time domain formulation of the theory of the tunnel junction, authors investigated Shapiro steps by digital simulation, under the condition of a constant current source given by I//d//c plus I//r//fsin omega t. The integral kernels for the Josephson and the quasiparticle current were computed assuming a nonzero pair breaking parameter delta equals 0. 1, and T equals OK. They obtained I//r//f dependence of the zeroth and first Shapiro steps, I//0 and I//1, and the frequency dependence of I//1**M**A**X, the maximum of the first Shapiro step as a function of I//r//f, for a few values of the junction capacitance.