Berlin 2012 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 21: Transport: Nanoelectronics I - Quantum Dots, Wires, Point Contacts 3
TT 21.6: Vortrag
Dienstag, 27. März 2012, 10:45–11:00, BH 334
Time scales in the dynamics of an interacting quantum dot — •Janine Splettstoesser1, Debora Contreras-Pulido1, Michele Governale2, Jürgen König3, and Markus Büttiker4 — 1Theorie für Statistische Physik, RWTH Aachen University — 2School of Physical and Chemical Sciences, Victoria University, Wellington, New Zealand — 3Theoretische Physik, Universität Duisburg-Essen — 4Physique Théorique, Université de Genève, Switzerland
The subject of this presentation is the relaxation behavior of an interacting quantum dot, brought out of equilibrium by a fast switch, e.g. of the gate potential [1,2]. We study a single-level quantum dot with strong Coulomb interaction, weakly coupled to a single lead, taking the role of a mesoscopic capacitor. The transient response to the fast change of an external parameter is computed by means of a real-time diagrammatic expansion in the tunnel-coupling strength.
We find that the exponential relaxation of the dot state is governed by three different time scales: Charge and spin relaxation depend on the final state of the dot and they differ from each other due to Coulomb repulsion. A further, gate-independent relaxation rate is related to electron-hole correlations and can be extracted, e.g., from deviations from the equilibrium charge. We study different setups and driving schemes to address the three independent decay rates separately.
J. Splettstoesser, M. Governale, J. König, and M. Büttiker, Phys. Rev. B 81, 165318 (2010).
L.-D. Contreras-Pulido, J. Splettstoesser, M. Governale, J. König, and M. Büttiker, arxiv:1111.4135.