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Incipient Wigner localization in circular quantum dots

Publication ,  Journal Article
Ghosal, A; Güçlü, AD; Umrigar, CJ; Ullmo, D; Baranger, HU
Published in: Physical Review B - Condensed Matter and Materials Physics
August 28, 2007

We study the development of electron-electron correlations in circular quantum dots as the density is decreased. We consider a wide range of both electron number, N≤20, and electron gas parameter, rs 18, using the diffusion quantum Monte Carlo technique. Features associated with correlation appear to develop very differently in quantum dots than in bulk. The main reason is that translational symmetry is necessarily broken in a dot, leading to density modulation and inhomogeneity. Electron-electron interactions act to enhance this modulation ultimately leading to localization. This process appears to be completely smooth and occurs over a wide range of density. Thus there is a broad regime of "incipient" Wigner crystallization in these quantum dots. Our specific conclusions are (i) the density develops sharp rings while the pair density shows both radial and angular inhomogeneity; (ii) the spin of the ground state is consistent with Hund's (first) rule throughout our entire range of rs for all 4≤N≤20; (iii) the addition energy curve first becomes smoother as interactions strengthen-the mesoscopic fluctuations are damped by correlation-and then starts to show features characteristic of the classical addition energy; (iv) localization effects are stronger for a smaller number of electrons; (v) finally, the gap to certain spin excitations becomes small at the strong interaction (large rs) side of our regime. © 2007 The American Physical Society.

Duke Scholars

Published In

Physical Review B - Condensed Matter and Materials Physics

DOI

EISSN

1550-235X

ISSN

1098-0121

Publication Date

August 28, 2007

Volume

76

Issue

8

Related Subject Headings

  • Fluids & Plasmas
  • 09 Engineering
  • 03 Chemical Sciences
  • 02 Physical Sciences
 

Citation

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Ghosal, A., Güçlü, A. D., Umrigar, C. J., Ullmo, D., & Baranger, H. U. (2007). Incipient Wigner localization in circular quantum dots. Physical Review B - Condensed Matter and Materials Physics, 76(8). https://doi.org/10.1103/PhysRevB.76.085341
Ghosal, A., A. D. Güçlü, C. J. Umrigar, D. Ullmo, and H. U. Baranger. “Incipient Wigner localization in circular quantum dots.” Physical Review B - Condensed Matter and Materials Physics 76, no. 8 (August 28, 2007). https://doi.org/10.1103/PhysRevB.76.085341.
Ghosal A, Güçlü AD, Umrigar CJ, Ullmo D, Baranger HU. Incipient Wigner localization in circular quantum dots. Physical Review B - Condensed Matter and Materials Physics. 2007 Aug 28;76(8).
Ghosal, A., et al. “Incipient Wigner localization in circular quantum dots.” Physical Review B - Condensed Matter and Materials Physics, vol. 76, no. 8, Aug. 2007. Scopus, doi:10.1103/PhysRevB.76.085341.
Ghosal A, Güçlü AD, Umrigar CJ, Ullmo D, Baranger HU. Incipient Wigner localization in circular quantum dots. Physical Review B - Condensed Matter and Materials Physics. 2007 Aug 28;76(8).

Published In

Physical Review B - Condensed Matter and Materials Physics

DOI

EISSN

1550-235X

ISSN

1098-0121

Publication Date

August 28, 2007

Volume

76

Issue

8

Related Subject Headings

  • Fluids & Plasmas
  • 09 Engineering
  • 03 Chemical Sciences
  • 02 Physical Sciences