Electron-electron interactions in isolated and realistic quantum dots: A density functional theory study

Journal Article

We use Kohn-Sham spin-density-functional theory to study the statistics of ground-state spin and the spacing between conductance peaks in the Coulomb blockade regime for both two-dimensional isolated and realistic quantum dots. We make a systematic investigation of the effects of electron-electron interaction strength and electron number on both the peak spacing and spin distributions. A direct comparison between the distributions from isolated and realistic dots shows that, despite the difference in the boundary conditions and confining potential, the statistical properties are qualitatively the same. Strong even/odd pairing in the peak spacing distribution is observed only in the weak e-e interaction regime and vanishes for moderate interactions. The probability of high spin ground states increases for stronger e-e interaction and seems to saturate around rs ∼4. The saturated value is larger than previous theoretical predictions. Both spin and conductance peak spacing distributions show substantial variation as the electron number increases, not saturating until N ∼150. To interpret our numerical results, we analyze the spin distribution in the even N case using a simple two-level model.

Full Text

Duke Authors

Cited Authors

  • Jiang, H; Ullmo, D; Yang, W; Baranger, HU

Published Date

  • June 1, 2004

Published In

Volume / Issue

  • 69 / 23

International Standard Serial Number (ISSN)

  • 0163-1829

Digital Object Identifier (DOI)

  • 10.1103/PhysRevB.69.235326

Citation Source

  • Scopus