Interaction and Quantum Decoherence in Disordered Conductors

Wepresent a nonperturbative approach which allows to evaluate the weak localization correction to the conductivity of disordered conductors in the presence of interactions. The effect of the electron-electron interaction on the magnetoconductance is described by the function A(t) exp(−f(t)). The dephasing 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 results the effect of interaction on the preexponent A(t) should be taken into account. The dephasing time cannot be unambiguously determined from a perturbative calculation.