  The possibility of existence of topological excitations in the anisotropic
quantum Heisenberg model in one and two spatial dimensions is studied using
coherent state method. It is found that a part of the Wess-Zumino term
contributes to the partition function, as a topological term for ferromagnets
in the long wavelength limit in both one and two dimensions. In particular, the
XY limit of the two-dimensional anisotropic ferromagnet is shown to retain the
topological excitations, as expected from the quantum Kosterlitz-Thouless
scenario.
