Breaking the Onsager symmetry: Rectification effects, nonequilibrium environments and shot noise

The Onsager relations applied to electronic transport establish that the
conductance of a two-terminal conductor is an even function of the
applied magnetic field. However, breakings of this symmetry may take
place in the nonlinear regime. We demonstrate that magnetoasymmetries
arise in mesoscopic systems only as a consequence of the charge response
of the conductor, thus being a pure interaction effect. Furthermore, we
investigate magnetoasymmetries in the linear response regime when a
mesoscopic system interacts with its environment. We show that the
interaction between the two systems causes an asymmetry when the
environment is out of equilibrium. Finally, we study the
magnetoasymmetric current fluctuations of a quantum dot in the
Coulomb-blockade regime. Interestingly, we find that the
magnetoasymmetries corresponding to the leading-order nonlinear
conductance and noise fulfill a higher-order fluctuation-dissipation
relationship.