Electronic structures in coupled two quantum dots by 3D-mesh Hartree-Fock-Kohn-Sham calculation
Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan
Corresponding author: a email@example.com
Published online: 15 September 2001
To study the electronic structures of quantum dots in the framework of self-interaction-free including three dimensional effects, we adopt the theory of nonlocal effective potential introduced by Kohn and Sham . For utilizing the advantageous point of the real space (3D) mesh method to solve the original nonlinear and nonlocal Hartree-Fock-Kohn-Sham (HFKS)-equation, we introduce a linearization of the equation in the local form by introducing the local Coulomb potentials which depend on explicitly the two single particle states. In practice, for solving the local form HFKS-equation, we use the Car-Parrinello-like relaxation method and the Coulomb potentials are obtained by solving the Poisson equation under proper boundary conditions. Firstly the observed energy gap between triplet- and singlet-states of N=4 in DBS  is discussed to reproduce the addition energies and chemical potentials depending the magnetic field. Next the coupling between two-quantum dots in TBS  is studied by adding the square barrier between two dots. The spin-degeneracy  measured in gate-voltage depending on magnetic field is well reproduced in the limit of small mismatch. Finally, the electronic states in the ring structure are calculated and discussed how the ring size and magnetic field affect to the structures.
PACS: 73.20.Dx – Electron states in low-dimensional structures (superlattices, quantum well structures and multilayers) / 71.15.Fv – Atomic- and molecular-orbital methods (including tight binding approximation, valence-bond method, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001