SINGLE-IMPURITY ANDERSON MODEL OUT OF EQUILIBRIUM

Transport through a localized site connected to two leads with differe nt chemical potentials-the Anderson model out of equilibrium-is invest igated via time-loop perturbation theory. The differential conductance is obtained from an analytic expression for the site density of state s, including a magnetic field. In addition to the usual Kondo peaks in the density of states which are shifted by the Zeeman energy from the chemical potentials, an additional peak is found to survive at one ch emical potential for each spin if the bias exceeds the Zeeman splittin g.