A new class of nodal stationary states in 2D Heisenberg ferromagnet

A new class of nodal topological excitations in a two-dimensional Heisenberg model is studied. The solutions correspond to a nodal singular point of the gradient field of the azimuthal angle. An analytical solution found for the isotropic case. An effect of in-plane exchange anisotropy is studied numerically. It results in solutions which are analogues of the conventional out-of-plane solitons in the two-dimensional magnets.