Density functional theory for a model quantum dot: Beyond the local-density approximation

Abstract

We study both static and transport properties of model quantum dots, employing density functional theory as well as (numerically) exact methods. For the lattice model under consideration the accuracy of the local-density approximation generally is poor. For weak interaction, however, accurate results are achieved within the optimized effective potential method, while for intermediate interaction strengths a method combining the exact diagonalization of small clusters with density functional theory is very successful. Results obtained from the latter approach yield very good agreement with density matrix renormalization group studies, where the full Hamiltonian consisting of the dot and the attached leads has to be diagonalized. Furthermore we address the question whether static density functional theory is able to predict the exact linear conductance through the dot correctly - with, in general, negative answer.

8 pages

References in corpus (5)

• Dynamical corrections to the DFT-LDA electron conductance in nanoscale systems
• Density functional calculations of nanoscale conductance
• Exact ground state density functional theory for impurity models coupled to external reservoirs and transport calculations
• Successes and failures of Bethe Ansatz Density Functional Theory
• Treatment of electron viscosity in quantum conductance