Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 15: Dual-Method Approaches to Quantum Many-Body Systems I

TT 15.10: Vortrag

Montag, 12. März 2018, 17:30–17:45, H 0104

The dynamic structure factor in impurity-doped spin chains — •Kevin Jägering¹, Annabelle Bohrdt², Sebastian Eggert¹, and Imke Schneider¹ — ¹Department of Physics and Research Center OPTIMAS, University of Kaiserslautern — ²Department of physics and Institute for Advanced Study, Technische Universität München, 85748 Garching, Germany

The effects of impurities in spin-1/2 Heisenberg chains are recently experiencing a renewed interest due to experimental realizations in solid state systems and ultra-cold gases. The impurities effectively cut the chains into finite segments with a discrete spectrum and characteristic correlations, which have a distinct effect on the dynamic structure factor. Using bosonization and the numerical Density Matrix Renormalization Group we provide detailed quantitative predictions for the momentum and energy resolved structure factor in doped systems. Due to the impurities, spectral weight is shifted away from the antiferromagnetic wave-vector k=π into regions which normally have no spectral weight in the thermodynamic limit. The effect can be quantitatively described in terms of scaling functions, which are derived from a recurrence relation based on bosonization. We present length-averaged and kintegrated results in terms of the doping concentration.