Interaction and quantum decoherence in disordered conductors

We present a nonperturbative approach which allows to evaluate the weak loc alization correction to the conductivity of disordered conductors in the pr esence of interactions. The effect of the electron-electron interaction on the magnetoconductance is described by the function A(t) exp( -f(t)). The d ephasing time is determined only by f(t), and this time remains finite down to T = 0 due to the electron-electron interactions. In order to establish the relation between our nonperturbative analysis and the perturbative resu lts the effect of interaction on the pre-exponent A(t) should be taken into account. The dephasing time cannot be unambiguously determined from a pert urbative calculation (C) 2000 Elsevier Science B.V. All rights reserved.