Shape of polygonal quantum dots and ground-state instability in the spin polarization

Masamu Ishizuki, Hannyo Takemiya, Takuma Okunishi, Kyozaburo Takeda, Kouichi Kusakabe

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

We theoretically investigate the ground-state electronic structure and the spin polarization of four electrons confined in two-dimensional (2D) polygonal quantum dots. We employ standard mean-field theory approaches using unrestricted Hartree-Fock (UHF) and density functional theory (DFT) calculations. Resonant UHF configuration interaction (res-UHF CI) calculations were also performed to incorporate the electron correlation more intuitively. Odd polygons (trigons and pentagons) preferentially generate the ground-state triplet as predicted by Hund's rule, whereas even polygons (tetragons, hexagons, and octagons) promote ground-state instability in the spin multiplicity and tend to produce an anti-Hund state of the ground-state singlet with strengthening of the interelectron interaction. The circle, a limited polygon having an infinite number of apexes, divides these odd and even polygons, and the ground-state instability can be well classified by the area of the polygon apexes that protrudes from an equisized circle.

Original languageEnglish
Article number155316
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume85
Issue number15
DOIs
Publication statusPublished - 2012 Apr 18

    Fingerprint

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this