Vortices in Quantum Spin Systems

TL;DR

This paper investigates the properties and dynamics of spin vortices in quantum Heisenberg models with planar anisotropy, revealing how classical vortex features are preserved in quantum states and providing a method to construct vortex-like excitations.

Contribution

It introduces a detailed analysis of quantum spin vortices, including symmetry properties and a construction scheme for vortex excitations from exact eigenstates applicable to various lattice types.

Findings

Classical vortex features are conserved in quantum spin states.

A construction scheme for vortex-like excitations from exact eigenstates is developed.

The approach is applicable to arbitrary spin lengths on different lattice geometries.

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.