Berlin 2012 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 45: Correlated Electrons: Poster Session

TT 45.55: Poster

Thursday, March 29, 2012, 15:00–19:00, Poster B

Lanczos algorithm with Matrix Product States for dynamical correlation functions — •Piet Dargel¹, Anton Wöllert², Andreas Honecker¹, and Thomas Pruschke¹ — ¹Institut für Theoretische Physik, Georg-August-Universität Göttingen — ²Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universität München

The Lanczos algorithm is combined with Matrix Product States to calculate dynamical correlation functions. The use of Matrix Product States allows to handle systems that are larger than those accessible within the standard Lanczos algorithm, for the price of worse convergence of the spectral poles as compared to the original algorithm. In order to achieve a better convergence of the spectral weights and poles we introduce an ex post reorthogonalization method and also test spectral shifts. We present results for the dynamic spin structure factor of the spin-1/2 antiferromagnetic Heisenberg chain. These results are compared to Bethe ansatz results in the thermodynamic limit.