Münster 1999 – scientific programme

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DY: Dynamik und Statistische Physik

DY 41: POSTER II

DY 41.34: Poster

Thursday, March 25, 1999, 09:30–13:00, Z

Vortices in Quantum Spin Systems — •John Schliemann and Franz G. Mertens — Physikalisches Institut, Universität Bayreuth

We examine spin vortices in ferromagnetic quantum Heisenberg models with planar anisotropy on two–dimensional lattices. The symmetry properties and the time evolution of vortices built up from spin–coherent states are studied in detail. Although these states show a dispersion typical for wave packets, important features of classical vortices are conserved. Moreover, the results on symmetry properties provide a construction scheme for vortex–like excitations from exact eigenstates, which have a well–controlled time evolution.
Our approach works for arbitrary spin length both on triangular and square lattices.