Coherent electronic transport in a multimode quantum channel with Gaussian-type scatterers

TL;DR

This paper investigates coherent electron transport in quantum wires with Gaussian scatterers, revealing conductance dips, resonant peaks, and effects of asymmetric potentials using a T-matrix approach.

Contribution

It introduces a T-matrix Lippmann-Schwinger formalism to analyze electron transport with Gaussian scatterers, including complex structures like quantum dots.

Findings

Reproduced known conductance dips due to attractive impurities.

Observed resonant peaks when electron energy matches quantum dot levels.

Identified two dips from quasi-bound states in asymmetric potentials.

Abstract

Coherent electron transport through a quantum channel in the presence of a general extended scattering potential is investigated using a T-matrix Lippmann-Schwinger approach. The formalism is applied to a quantum wire with Gaussian type scattering potentials, which can be used to model a single impurity, a quantum dot or more complicated structures in the wire. The well known dips in the conductance in the presence of attractive impurities is reproduced. A resonant transmission peak in the conductance is seen as the energy of the incident electron coincides with an energy level in the quantum dot. The conductance through a quantum wire in the presence of an asymmetric potential are also shown. In the case of a narrow potential parallel to the wire we find that two dips appear in the same subband which we ascribe to two quasi bound states originating from the next evanescent mode.