Regensburg 2007 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 20: Correlated Electrons - Poster Session

TT 20.79: Poster

Mittwoch, 28. März 2007, 14:00–17:45, Poster A

Deconvolution procedures for dynamical DMRG spectra — •Martin Paech and Eric Jeckelmann — Institut fuer Theoretische Physik, Leibniz Universitaet Hannover

The dynamical density-matrix renormalization group (DDMRG) method provides the frequency-dependent correlation functions of finite-size low-dimensional systems with great accuracy. The spectrum of an infinite system can be obtained for each frequency separately using a finite-size scaling analysis of the DDMRG data. We have shown previously that the infinite-system spectrum can sometimes be obtained at a much lower computational cost by a deconvolution of the finite-system DDMRG data under some regularity assumptions for the spectrum. Although standard algorithms for inverse problems such as a deconvolution yield good results for smooth continuous spectra they fail if the spectrum includes singularities. We discuss several deconvolution procedures for general spectra and illustrate them with a study of the density of states in one-dimensional correlated electron systems.