  We investigate theoretically the behavior of the current oscillations in an
electronic Mach-Zehnder interferometer (MZI) as a function of its source bias.
Recently, The MZI interference visibility showed an unexplained lobe pattern
behavior with a peculiar phase rigidity. Moreover, the effect did not depend on
the MZI paths difference. We argue that these effects may be a new many-body
manifestation of particle-wave duality of quantum mechanics. When biasing the
interferometer sources beyond the linear response regime, quantum shot-noise (a
particle phenomena) must affect the interference pattern of the electrons that
creates it, as a result from a simple invariance argument. An approximate
solution of the interacting Hamiltonian indeed shows that the interference
visibility has a lobe pattern with applied bias with a period proportional to
the average path length and independent of the paths difference, together with
a phase rigidity.
