Regensburg 2010 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 27: CE: Poster Session

TT 27.80: Poster

Mittwoch, 24. März 2010, 14:00–18:00, Poster D1

Dynamics of magnetic impurities in two-dimensional spin-1/2 antiferromagnets — •Björn Willenberg and Wolfram Brenig — Institut für Theoretische Physik, Technische Universität Braunschweig

Using Quantum Monte-Carlo methods based on the stochastic series expansion we investigate the dynamics of a single spin-1/2-degree of freedom coupled to a two-dimensional Heisenberg antiferromagnet (HAFM). Calculating imaginary time spin correlation functions and performing Maximum Entropy analysis we analyze the dynamical longitudinal and transverse local susceptibilities of the impurity. These quantities will be studied as a function of temperature and system size. Our findings will be compared to analytical results from stochastic Liouville equations. Finally we discuss the role of antiferro- versus ferromagnetic coupling of the impurity to the HAFM.