Dresden 2006 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 5: Transport: Nanoelectronics I - Quantum Dots, Wires, Point Contacts - Part 1

TT 5.1: Hauptvortrag

Montag, 27. März 2006, 09:30–10:00, HSZ 304

Correlation effects on electronic transport through dots and wires — •Volker Meden — Institut für Theoretische Physik, Universität Göttingen

We investigate how two-particle interactions affect the electronic transport trough several meso- and nanoscopic systems made of two building blocks: quasi one-dimensional quantum wires of interacting electrons and quantum dots with local Coulomb correlations. A recently developed functional renormalization group scheme is used that includes the essential aspects of Tomonaga-Luttinger liquid physics (one-dimensional wires) as well as of the physics of local correlations, with the Kondo effect being an important example. We describe the appearance of a variety of surprising correlation effects. (1) For a Y-junction of wires pierced by a magnetic flux we find a regime in which correlations restore time-reversal symmetry. (2) We investigate the interplay of Tomonaga-Luttinger physics and the Kondo effect in transport through a single site dot with interacting leads. Studied separately, the first leads to a sharp Lorentz-like resonance in the gate voltage dependence of the linear conductance while the latter implies a broad plateau-like resonance. (3) We find a pair of novel correlation induced resonances in the gate voltage dependence of the linear conductance through a parallel double-dot systems that results from the interplay of correlations and quantum interference. It should be observable in experiments on the basis of presently existing double-dot setups. An outlook on future application of the functional renormalization group scheme in mesoscopic physics is given.