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TT: Tiefe Temperaturen

TT 22: Transport - Nanoelectronics II: Quantum Dots and Wires, Point Contacts

TT 22.12: Vortrag

Montag, 7. März 2005, 17:00–17:15, TU H2053

Spin and Charge Channels in Zero Dimensional Systems — •Mikhail Kiselev¹ and Yuval Gefen² — ¹Institut für Theoretische Physik, Universität Würzburg, D-97074 Würzburg, Germany — ²Department of Condensed Matter Physics, The Weizmann Institute of Science, Rehovot 76100, Israel

We consider the effects of the charge and spin zero-mode interactions in quantum dots. The non-perturbative effects of zero-mode interaction are described in terms of the propagation of gauge bosons associated with U(1) charge and SU(2) spin fluctuations in the dot. The Coulomb and longitudinal spin components are accounted for "exactly", while transverse spin fluctuations are analyzed perturbatively (with the easy-axis anisotropy). These fluctuations become important as one approaches the Stoner instability. We study the influence of spin on the differential conductance as well as the dynamic spin susceptibility.