Conductance of interacting Aharonov-Bohm systems

A simple formula for the zero-temperature linear response conductance of an interacting mesoscopic region, threaded by magnetic flux, and attached to noninteracting single-channel leads is presented. The formula is valid for a general interacting system exhibiting Fermi liquid properties. As an example of the efficiency of the formula the results for the conductance of a simple Aharonov-Bohm ring with Kondo-Fano resonance physics are presented and compared with numerical renormalization group results.