Berlin 2012 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 12: Transport: Nanoelectronics I - Quantum Dots, Wires, Point Contacts 2
TT 12.5: Vortrag
Montag, 26. März 2012, 16:00–16:15, BH 334
Zero-temperature non-linear quantum transport through quantum dots: real-time renormalization-group (RT-RG) calculation of dI/dV stability diagrams — •Roman Saptsov1,2, Maarten Wegewijs1,2,3, and Herbert Schoeller2,3 — 1Peter Gruenberg Institut, Forschungszentrum Juelich, 52425 Juelich, Germany — 2JARA- Fundamentals of Future Information Technology — 3Institute for Theory of Statistical Physics, RWTH Aachen, 52056 Aachen, Germany
The recently developed RT-RG approach was applied to study the non-linear transport through a quantum dot described by the Anderson impurity model. The RT-RG equations were solved numerically including both 1- and 2- loop orders in the limit of zero temperature and non-linear transport voltages where most standard theoretical methods break down. We predict non-perturbative tunneling effects in the transport stability diagram which can be measured experimentally. Moreover, we found the exact functional form of the renormalized spectra of the dot at any loop order. In the non-interacting case we show that the RT-RG recovers the exact solution within our 2 loop approach. In the strong-interacting limit the method breaks down as expected only at very small voltages on the order of the Kondo temperature, which we illustrate by comparison with the Friedel sum rule.