Onsager asymmetries and nonequilibrium fluctuation-dissipation relations
in mesoscopic conductors
University of the Balearic Islands, Spain
Monday, October 19, 2009, 3:15 PM
In the nonlinear regime of electron transport, screening effects can
lead to a breakdown of microreversibility in mesoscopic systems. The
nonequilibrium response of the potential landscape along the system is,
quite generally, an uneven function of the magnetic field, implying a
magnetoasymmetry of the differential conductance . This effect has
been observed in many different phase-coherent conductors. Recent
theoretical developments relate the asymmetry of the noise to the
asymmetry of the differential conductance in the leading order of a
voltage expansion [2,3]. As a consequence, a higher-order fluctuation
dissipation relation (FDR) is established between the two
magnetoasymmetries even when fluctuation theorems are not obeyed. Here,
we discuss the magnetoasymmetries arising in the current fluctuations of
quantum dots with strong Coulomb correlations and explicitly demonstrate
the validity of nonequilibrium FDRs when interactions are treated beyond
the mean field approximation .
 D. Sanchez and M. Buttiker, Phys. Rev. Lett. 93, 106802 (2004).
 H. Forster and M. Buttiker, Phys. Rev. Lett. 101, 136805 (2008).
 D. Sanchez, Phys. Rev. B 79, 045305 (2009).
 J.S. Lim, D. Sanchez, and R. Lopez (unpublished, 2009).