Non-linear magneto-transport through small quantum dots at strong intra-dot correlations

Nonlinear transport through a quantum dot is studied in the limit of weak and strong intra-dot Coulomb interaction. For the latter regime the nonequilibrium self-consistent mean field equations for energies and spectral weights of one-electron transitions are formulated. The increase of the bias-voltage window leads to a strong deviation from Gibbs statistics: the populations of states involved into a tunnelling are equalizing in this limit even at low temperature. For a symmetric coupling of a quantum dot to two leads we provide simple analytical relations between heights of the current steps and degeneracy of a spectrum in a two-dimensional parabolic dot in a perpendicular magnetic field in the both regimes.