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HL: Halbleiterphysik
HL 32: Quantendots II
HL 32.5: Vortrag
Donnerstag, 20. März 1997, 16:30–16:45, H2
Resonant Tunneling through a Two-Level Dot and Double Quantum Dots — •T. Pohjola1,2, J. König2, M. Salomaa1, J. Schmid2, H. Schoeller2, and Gerd Schön2 — 1Materials Physics Laboratory, Department of Engineering Physics and Mathematics, Helsinki University of Technology, 02150 Espoo, Finland — 2Institut für Theoretische Festkörperphysik Universität Karlsruhe, D-76128 Karlsruhe
Motivated by recent experiments we study resonant tunneling through quantum-dot systems in the presence of strong Coulomb repulsion and strong coupling between the dot(s) and metallic leads. We concentrate on two quantum-dot systems, both situated between reservoirs: (i) a single dot with two energy levels and (ii) a double dot with just one level in each dot. Using a real-time diagrammatic formulation we calculate transition rates, the spectral density, and the nonlinear I−V characteristic. It appears that we can achieve two different Kondo models in the two extremes of our model, i.e. zero or infinite level separation. With finite level separation we find a novel triple-peak resonant structure in the nonlinear conductance.