Dresden 2011 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 44: Poster Session Correlated Electrons

TT 44.62: Poster

Thursday, March 17, 2011, 10:00–13:00, P1

Properties of dimerized n-leg spin 1/2 ladders — •Kris Cöster and Kai Phillip Schmidt — Lehrstuhl für Theoretische Physik I, TU Dortmund, 44221 Dortmund, Germany

The Heisenberg model on quasi one-dimensional ladder structures is expected to be interesting since it interpolates between the purely one-dimensional case having fractional excitations and the two-dimensional system displaying long-range order. In recent years there has been a big process in the theoretical and experimental understanding of the two-leg ladder. But the microscopic determination of the excitation spectrum and the spectral properties of n-leg ladders is very challenging.

Here we approach the general case by studying dimerized n-leg ladders with n=3,4,5,6. To this end we use perturbative continuous unitary transformations (pCUTs) with advanced graph techniques to obtain an effective quasi-particle description. We calculate the one- and two-triplon properties. Special regard is paid to binding effects between two triplons with total spin zero which is of direct relevance for optical spectroscopy on such systems.