Dresden 2003 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 20: Postersitzung IV (Mesoskopische Systeme, Supraleitung: Massivmaterialien, Bandleiter, Pinning, Vortexdynamik, Transporteigenschaften, Korngrenzen)
TT 20.20: Poster
Donnerstag, 27. März 2003, 14:30–19:00, P2c, P2d
Effective Line Width in Interacting Quantum Dots — •Björn Kubala and Jürgen König — Institut für Theoretische Festkörperphysik, Universität Karlsruhe, 76128 Karlsruhe, Germany
We investigate the width Γ of Coulomb oscillation peaks in the electrochemical capacitance ∂ Q / ∂ Vg in small quantum dots. For small coupling, Γ is given by max{kBT,Γ}, where Γ is the golden-rule level width. For strong coupling charging effects are suppressed, resulting in less pronounced peaks with a width of the order of the charging energy. While the extreme limits of weak and strong coupling are well understood the crossover is rather puzzling.
We want to investigate this crossover by employing the real-time renormalization group technique by Schoeller [1]. We study the occupation number of a two level quantum dot with e-e interaction coupled to a reservoir and extract Γ(Γ). This RTRG approach is also applicable to the study of (non-equilibrium) transport properties of interacting quantum dots.
[1] H. Schoeller, cond-mat/9909400; H. Schoeller and J. König, Phys. Rev. Lett. 84, 3686 (2000).