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TT: Fachverband Tiefe Temperaturen

TT 35: Postersession Transport: Nanoelectronics, Quantum Coherence and Quantum Information, Fluctuations and Noise

TT 35.15: Poster

Mittwoch, 25. März 2009, 14:00–18:00, P1A

Geometry-Dependence of 0.7 Anomaly in Quantum Point Contacts: A Study Using the Functional Renormalization Group — •Jan Heyder, Florian Bauer, and Jan von Delft — Arnold Sommerfeld Center for Physics, Ludwig-Maximilians-Universitaet, Muenchen

We study the geometry-dependence of the 0.7 anomaly of the conductance through a quantum point contact at zero temperature as a function of magnetic field, using the functional renormalization group (fRG). We model a 1-D quantum wire using a tight-binding chain with short-ranged Coulomb interactions and a prescribed onsite potential to mimick the potential barrier caused by the 2-D constriction. We study the influence of various shapes of this potential barrier on the magnetic-field dependence of the conductance, finding that it indeed does show a significant geometry-dependence.