Signature of the electron-electron interaction in the magnetic-field dependence of nonlinear I-V characteristics in mesoscopic conductors

The nonlinear I-V characteristics of mesoscopic samples contain parts which are linear in a magnetic field and quadratic in voltage. These contributions to the current are entirely due to the electron-electron interaction, and consequently they are proportional to the electron-electron interaction constant. We present detailed calculations of the magnitude of the effect as a function of the temperature and the direction of the magnetic field. We show that in the case of a magnetic field oriented parallel to the sample, the effect exists entirely due to spin-orbit scattering. The temperature dependence of the magnitude of the effect has an oscillating character with a characteristic period on the order of the temperature itself. We also clarify the nature of the electron-electron interaction constant which determines the magnitude of the effect.