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

    Spin polarization
    polygons
    Ground state
    Semiconductor quantum dots
    quantum dots
    ground state
    polarization
    tetragons
    apexes
    Electron correlations
    Mean field theory
    hexagons
    Strengthening (metal)
    configuration interaction
    Electronic structure
    Density functional theory
    electrons
    density functional theory
    electronic structure
    Electrons

    ASJC Scopus subject areas

    • Condensed Matter Physics
    • Electronic, Optical and Magnetic Materials

    Cite this

    Shape of polygonal quantum dots and ground-state instability in the spin polarization. / Ishizuki, Masamu; Takemiya, Hannyo; Okunishi, Takuma; Takeda, Kyozaburo; Kusakabe, Kouichi.

    In: Physical Review B - Condensed Matter and Materials Physics, Vol. 85, No. 15, 155316, 18.04.2012.

    Research output: Contribution to journalArticle

    Ishizuki, Masamu ; Takemiya, Hannyo ; Okunishi, Takuma ; Takeda, Kyozaburo ; Kusakabe, Kouichi. / Shape of polygonal quantum dots and ground-state instability in the spin polarization. In: Physical Review B - Condensed Matter and Materials Physics. 2012 ; Vol. 85, No. 15.
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