SKM 2021 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 8: Poster Session II
HL 8.22: Poster
Dienstag, 28. September 2021, 10:00–13:00, P
Kondo effect in a few-electron quantum dot — •Olfa Dani1, Johannes C. Bayer1, Timo Wagner1, Gertrud Zwicknagl2, and Rolf J. Haug1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, Germany — 2Institut für Mathematische Physik, Technische Universität Braunschweig, Germany
The Kondo effect is a many particle entangled system, that involves the interaction between a localized spin in the quantum dot and free electrons in the electron reservoirs. This entanglement can be however exactly calculated for models adopting simplifying assumptions concerning the electronic structure of the quantum dot.
The investigated quantum dot device is based on a flat two-dimensional electron gas (2DEG) formed in a GaAs/AlGaAs heterostructure. A single quantum dot is formed in this 2DEG using top-gates and a quantum point contact (QPC) is operated as sensitive charge detector, allowing the real-time detection of electrons tunneling through the system [1].
The Kondo effect dominates at a strong coupling between dot and leads. It gives rise to a finite conductance in the otherwise Coulomb-blockaded regime, and has a characteristic temperature dependence. Here we study the Kondo effect as a function of the tunnel coupling and its symmetry. For small number of electrons, we see that the shell structure[2] of the electronic states in the quantum dot influence the Kondo effect.
[1] T. Wagner, et. al., Nat. Nanotech. 12, 218-222 (2017).
[2] L. P. Kouwenhoven, Rep. Prog. Phys. 64, 701-736 (2001).