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Coulomb correlation effects in semiconductor quantum dots: The role of dimensionality

Massimo Rontani·Fausto Rossi·Franca Manghi·Elisa Molinari
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Abstract

We study the energy spectra of small three-dimensional (3D) and two-dimensional (2D) semiconductor quantum dots through different theoretical approaches (single-site Hubbard and Hartree-Fock hamiltonians); in the smallest dots we also compare with exact results. We find that purely 2D models often lead to an inadequate description of the Coulomb interaction existing in realistic structures, as a consequence of the overestimated carrier localization. We show that the dimensionality of the dots has a crucial impact on (i) the accuracy of the predicted addition spectra; (ii) the range of validity of approximate theoretical schemes. When applied to realistic 3D geometries, the latter are found to be much more accurate than in the corresponding 2D cases for a large class of quantum dots; the single-site Hubbard hamiltonian is shown to provide a very effective and accurate scheme to describe quantum dot spectra, leading to good agreement with experiments.

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Massimo Rontani, Fausto Rossi, Franca Manghi, Elisa Molinari. 1998-12-30. Coulomb correlation effects in semiconductor quantum dots: The role of dimensionality. https://doi.org/10.1103/physrevb.59.10165

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