Eur. Phys. J. B 9, 237-243 (1999)
https://doi.org/10.1007/s100510050762

Vortices in quantum spin systems

Physikalisches Institut, Universität Bayreuth, 95440 Bayreuth, Germany

Received: 2 October 1998
Published online: 15 May 1999

Abstract

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.