Novel circuit theory of Andreev reflection

We review here a novel circuit theory of superconductivity. The existing ci rcuit theory of Andreev reflection has been revised to account for decohere nce between electrons and holes and the twofold nature of the distribution function. The description of arbitrary connectors has been elaborated on. I n this way one can cope with most of the factors that limited the applicabi lity of the old circuit theory. We give a simple example and discuss numeri cal implementation of the theory. (C) 1999 Academic Press.