Non-equilibrium transport phenomena in low-dimensional quantum systems

In this thesis we have introduced and extensively studied a model for describing some essential non-equilibrium transport properties of a quantum system with reduced dimensionality. The problem of finding some of the kinetic characteristics of such a model system is formulated as that of finding a solution of a tunneling Hamiltonian with a Hubbard term. To solve this Hamiltonian we first make use of the path integral formalism, generalized for systems far from equilibrium, to perform the quantum-statistical average. The spectral function for the electrons in the well is calculated for different relevant sets of parameters. The possible presence of a Kondo peak in the interacting density of states is discussed. We calculate the frequency-driven conductance and energy losses in the linear response approximation. Numerical simulations of the general expressions show that for a given set of parameters consistent with the particular physical situation of interest, a resonant behavior is obtained for both the conductance and energy absorption for external frequencies equal to the Coulomb repulsion energy E(C).