  The nonlinear electronic transport properties of a ballistic Aharonov-Bohm
ring are investigated. It is demonstrated how the electronic interaction breaks
the phase rigidity in a two-probe mesoscopic device as the voltage bias is
increased. The possibility of studying interference effects in the nonlinear
regime is addressed. The occurrence of magnetic feld symmetries in higher order
conductance coefficients is analyzed. The results are compared with recent
experimental data.
