Key points are not available for this paper at this time.
A functional-integral formulation is used to treat the quantum dynamics of a microscopic model of a Josephson junction, including the dissipative effects of quasiparticle tunneling. The calculation is carried to a point where it makes contact with, and therefore substantiates, recent work by Caldeira and Leggett in which the system is treated by analogy with the quantum Brownian motion of a massive particle coupled to a phenomenological heat bath.
Ambegaokar et al. (Mon,) studied this question.