Influence Functional for Decoherence of Interacting Electrons in Disordered Conductors

Abstract

We have rederived the controversial influence functional approach of Golubev and Zaikin (GZ) for interacting electrons in disordered metals in a way that allows us to show its equivalence, before disorder averaging, to diagrammatic Keldysh perturbation theory. By representing a certain Pauli factor (1-2 rho) occuring in GZ's effective action in the frequency domain (instead of the time domain, as GZ do), we also achieve a more accurate treatment of recoil effects. With this change, GZ's approach reproduces, in a remarkably simple way, the standard, generally accepted result for the decoherence rate. -- The main text and appendix A.1 to A.3 of the present paper have already been published previously; for convenience, they are included here again, together with five additional, lengthy appendices containing relevant technical details.

Final version, as submitted to IJMPB. 106 pages, 11 figures. First 16 pages contain summary of main results. Appendix A summarizes key technical steps, with a new section A.4 on "Perturbative vs. Nonperturbative Methods". Appendix C.4 on thermal weighting has been extended to include discussion [see Eqs.(C.22-24)] of average energy of electron trajectories