We revisited the scaling behavior of the transport properties of a quantum dot system described by the spin-1/2 Anderson model using analytical methods. In the low temperature limit we show that the conductance has a universal behavior with universal
ity between temperature and bias. We compare this result with the empirical formula used to fit the experimental data for conductance in the case of the equilibrium transport through a single channel quantum dot. In the high temperature limit the conductance obtained from the Anderson model is compared with previous results obtained from the Kondo model. The universal behavior is present also in the high temperature limit. These results are in good agreement with the Renormalization group calculations.
We calculate the plasmon dispersion in quasi-one-dimensional quantum wires, in the presence of non-magnetic impurities, taking into consideration the memory function formalism and the role of the forward scattering. The plasma frequency is reduced by
the presence of impurities. We also calculate, analytically, the plasmon dispersion in the Born approximation, for the scattering of the electrons by the non-magnetic impurities. We compare our result with the numerical results of Sarma and Hwang.
We consider the two dimensional disordered Bose gas which present a metallic state at low temperatures. A simple model of an interacting Bose system in a random field is propose to consider the interaction effect on the transition in the metallic state.
