Electronic correlation in nanoscale junctions : Comparison of the GW approximation to a numerically exact solution of the single-impurity Anderson model

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • X. Wang
  • C. D. Spataru
  • M. S. Hybertsen
  • A. J. Millis

Detail(s)

Original languageEnglish
Article number45119
Journal / PublicationPhysical Review B - Condensed Matter and Materials Physics
Volume77
Issue number4
Publication statusPublished - 15 Jan 2008
Externally publishedYes

Abstract

The impact of electronic correlation in nanoscale junctions, e.g., formed by single molecules, is analyzed using the single-impurity Anderson model. Numerically exact quantum Monte Carlo calculations are performed to map out the orbital filling, linear response conductance, and spectral function as a function of the Coulomb interaction strength and the impurity level position. These numerical results form a benchmark against which approximate but more broadly applicable approaches to include electronic correlation in transport can be compared. As an example, the self-consistent GW approximation has been implemented for the Anderson model and the results have been compared to this benchmark. For weak coupling or for level positions such that the impurity is either nearly empty or nearly full, the GW approximation is found to be accurate. However, for intermediate or strong coupling, the GW approximation does not properly represent the impact of spin or charge fluctuations. Neither the spectral function nor the linear response conductance is accurately given across the Coulomb blockade plateau and well into the mixed valence regimes. © 2008 The American Physical Society.

Citation Format(s)

Electronic correlation in nanoscale junctions : Comparison of the GW approximation to a numerically exact solution of the single-impurity Anderson model. / Wang, X.; Spataru, C. D.; Hybertsen, M. S.; Millis, A. J.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 77, No. 4, 45119, 15.01.2008.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review