Berlin 2012 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 21: Transport: Nanoelectronics I - Quantum Dots, Wires, Point Contacts 3
TT 21.1: Vortrag
Dienstag, 27. März 2012, 09:30–09:45, BH 334
Quantum spin relaxation by a nonequilibrium current — •Daniel Becker1,2, Stephan Weiss2, Michael Thorwart2, and Daniela Pfannkuche2 — 1Department Physik, Universität Basel, 4056 Basel, Schweiz — 2I. Institut für Theoretische Physik, Universität Hamburg, 20355 Hamburg
For a Coulomb-interacting single-level quantum dot in contact with two metallic leads and a spin-1/2 magnetic impurity, which is exchange-coupled to the electron spin, the interplay between the correlated charge- and (interaction-induced) real-time impurity dynamics is studied. To this end, the numerically exact, non-perturbative scheme of iterative summation of path integrals (ISPI)[1,2] is employed in a regime, where all appearing energy scales are of the same order of magnitude. A systematical investigation of the mutual dependencies between charge current and impurity relaxation dynamics is provided. By comparison to a perturbative theory both for (a) the case of either vanishing Coulomb- or electron-impurity interaction and (b) non-vanishing interactions, it is clearly shown that correlation effects due to the on-dot interactions considerably affect the system behavior. In particular, our approach reveals how a quantum spin relaxes to its stationary state under the influence of a nonequilibrium current.
S. Weiss et al., Phys. Rev. B 77, 195316 (2008)
D. Becker et al., J. Phys.: Conf. Ser. 245 012021 (2010)