Nonequilibrium transport in the Anderson model of a biased quantum dot:Scattering Bethe ansatz phenomenology

摘要

We derive the transport properties of a quantum dot subject to a source-drain bias voltage at zero temperature and magnetic field. Using the scattering Bethe anstaz, a generalization of the traditional thermodynamic Bethe ansatz to open systems out of equilibrium, we derive results for the quantum dot occupation in and out of equilibrium and, by introducing phenomenological spin- and charge-fluctuation distribution functions in the computation of the current, obtain the differential conductance for large u/v. The Hamiltonian to describe the quantum dot system is the Anderson impurity Hamiltonian and the current and dot occupation as a function of voltage are obtained numerically. We also vary the gate voltage and study the transition from the mixed valence to the Kondo regime in the presence of a nonequilibrium current. We conclude with the difficulty we encounter in this model and a possible way to solve it without resorting to a phenomenalogical method.