Signal transport and finite bias conductance in and through correlated nanostructures

Abstract

During the past decade improved experimental techniques have made production of and measurements on one-dimensional systems possible, and hence led to an increasing theoretical interest in these systems. However, the description of non-equilibrium transport properties, like the signal transport or the finite bias conductance of an interacting nanostructure attached to leads, is a challenging task. For non-interacting particles, the conductance can be extracted from the transmission of the single particle levels. However, the screening of electrons is reduced by reducing the size of structures under investigation and electron-electron correlations can no longer be neglected. Therefore, an adequate description has to be able to treat strong correlations and non-equilibrium in a rigorous manner. While several methods have been developed to calculate the zero bias conductance of strongly interacting nanostructures, there are no general methods available to obtain rigorous results for the finite bias conductance. While the problem has been formally solved by Meir and Wingreen using Keldysh Greens functions [1], the evaluation of these formulas for interacting systems is generally based on approximate schemes. In this project we apply the real time density matrix renormalization group method (RT-DMRG) to simulate the signal transport in one-dimensional, interacting quantum systems, and the conductance of interacting nanostructures attached to one-dimensional, non-interacting leads, where the nanostructure and the leads are described with a time dependent many particle wavefunction.