Regensburg 2010 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 8: CE: (General) Theory

TT 8.7: Talk

Monday, March 22, 2010, 15:30–15:45, H21

Dynamical Vertex Approximation for nanosystems — •Angelo Valli, Giorgio Sangiovanni, and Karsten Held — Institut für Festkörperphysik, TU Wien

In the spirit of Dynamical Vertex Approximation (DΓA), we propose a computational approach which assumes the locality of the n-particle fully irreducible vertex to treat nanoscopic systems. To test the reliability of our scheme, we compare it in its simplest version (n=1) to numerically exact Quantum Monte Carlo for a multi-site Anderson Impurity Model when the number of correlated atoms is small. We focus on quantities like electronic spectra and double occupancies and compare them to alternative methods [1]. The nanoscopic DΓA has the advantage that the simulation of a much larger number of coupled nanosystems is possible than for the exact solution, e.g., an ensemble of coupled quantum dots, macromolecules, or a cluster of ad atoms on surfaces.

[1] S. Florens, PRL99, 046402 (2007)