Many-electron effects on ballistic transport

A Thomas-Fermi-Dirac\char21{}von Weizs\"acker density-functional formalism is used to study the effects of many-electron Coulomb interactions on quantum transport through two-dimensional semiconductor nanostructures. The electron density is obtained by direct minimization of the total energy functional, and an effective potential for the electrons is determined as a functional of the density self-consistently. Transmission coefficient and conductance are computed with the effective potential included. The electron density distribution as well as the effective potential are strongly affected by the average electron density and the distance between the two-dimensional electron gas and the positive background charge. The transmission property of a stadium-shaped open quantum-dot system is investigated by varying these system parameters. The electron ballistic transport problem is solved in the presence of the many-electron effective potential and results are compared to that of the single-electron approximation. Some important differences are observed.