Comments on the roles of the cosine term and the reactive part of the quasiparticle term in the Josephson tunneling current

A short summary of the theory of Josephson tunneling in the presence of a time-dependent voltage is given. It is shown that neither the reactive part of the quasiparticle current nor the cosine term contributes directly to the time-averaged current. However, non-zero frequency components of these two terms can interact with a circuit in such a way as to alter the voltage and therefore the time-averaged current arising from the quasiparticle and sine terms. The importance of the reactive part of the quasiparticle and cosine terms is considered briefly at high frequencies.