Dresden 2017 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 27: Computational Materials Modelling - Electronic structure approaches

MM 27.4: Vortrag

Dienstag, 21. März 2017, 11:00–11:15, IFW B

Analytical continuation of Green’s functions using Padé approximants — •Johan Schott — Uppsala University, Uppsala, Sweden

A critical step to obtain physical observables for many Green’s function based methods is the ill-posed analytical continuation problem. We propose to remedy the known instability problems of the Padé approximant method by averaging several continuations, using different number of Padé approximant coefficients and input points. In our article [Phys. Rev. B 93, 075104 (2016)] we also show including negative Matsubara frequencies further improves the peak resolution possibility. The importance of high numerical precision, even for very noisy input data, is systematically presented. Lastly, the presented method is compared to a number of other analytical continuation methods, showing good performance.