Sign of the cos phi conductance term in Josephson tunneling

Unlike the Josephson supercurrent, j(c) sin phi, the quasiparticle conducta nce current (sigma(0)+sigma(1) cos phi)V, of a Josephson junction is dissip ative. For many years the theoretical consensus has been that sigma(1) must be positive. The discrepancy in sign between belief and observation is res olved herein by showing that the theoretical sign of sigma(1) is, in fact, negative.