Electronic exchange in quantum rings: Beyond the local-density approximation

E. Räsänen, S. Pittalis, C. R. Proetto, E. K. U. Gross

Research output: Contribution to journalArticleScientificpeer-review

21 Citations (Scopus)

Abstract

Quantum rings can be characterized by a specific radius and ring width. For this rich class of physical systems, an accurate approximation for the exchange-hole potential and thus for the exchange energy is derived from first principles. Excellent agreement with the exact-exchange results is obtained regardless of the ring parameters, total spin, current, or the external magnetic field. The description can be applied as a density functional outperforming the commonly used local spin-density approximation, which is here explicitly shown to break down in the quasi-one-dimensional limit. The dimensional crossover, which is of extraordinary importance in low-dimensional systems, is fully captured by our functional.

Original languageEnglish
Article number121305
Number of pages4
JournalPhysical Review B
Volume79
Issue number12
DOIs
Publication statusPublished - Mar 2009
Externally publishedYes
Publication typeA1 Journal article-refereed

Keywords

  • ab initio calculations
  • density functional theory
  • quantum dots
  • FUNCTIONAL THEORY
  • ENERGY-SPECTRA
  • STATES
  • MODEL
  • DOTS

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