Periodicity of transport coefficients with half flux quanta in the Aharonov-Bohm effect

Abstract
We prove that all transport coefficients of a dirty normal metal in the Aharonov-Bohm geometry are exactly periodic with a period of a half flux quantum. This special periodicity appears only after performing the ensemble average over a symmetric distribution of random potentials. This result indicates how to improve numerical studies of localization by selectively averaging over the ensemble in such a manner as to preserve the special symmetries of the Hamiltonian.