Greifswald 2009 – scientific programme

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P: Fachverband Plasmaphysik

P 18: Poster: Theorie/Modellierung

P 18.26: Poster

Wednesday, April 1, 2009, 17:30–19:30, Foyer des IfP

Few-electron quantum dots within a nonequilibrium Green’s functions study — Karsten Balzer, David Hochstuhl, and •Michael Bonitz — Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universität Kiel, Leibnizstrasse 15, 24098 Kiel, Germany

Carrier-carrier correlations in few-electron quantum dots (QDs)—artificial atoms [1] with parabolic confinement— are studied by means of nonequilibrium Green’s functions (NEGF) theory. Starting from an (un)restricted Hartree-Fock reference state, the Dyson equation is solved in the time domain [2] at zero and finite temperatures including 2nd Born and GW interaction kernels. We focus on strongly correlated QDs, the electron density in which is tunable by the strength of the confining potential. Considering system sizes with up to 12 electrons in one- and two-dimensional confinements, the computed ground state and equilibrium properties incorporate the self-consistent total energies, the single-carrier densities, the orbital-resolved distribution functions as well as the one-electron spectral functions [2]. The comparison of the results with Configuration Interaction [3,4] and path integral Monte Carlo [4,5] comprises the crossover from Fermi liquid to Wigner molecule or crystal behavior [5] and reveals good agreement with the NEGF approach.

[1] R.C. Ashoori, Nature 379, 413 (1996). [2] K. Balzer et al., submitted to Phys. Rev. B (2008). [3] B. Reusch et al., Phys. Rev. B 63, 113313 (2001). [4] M. Rontani et al., J. Chem. Phys. 124. 11 (2006). [5] A.V. Filinov et al., Phys. Rev. Lett. 86, 17 (2001).