Magnetic Vortex Induced by Nonmagnetic Impurity in Frustrated Magnets

We study the effect of a nonmagnetic impurity inserted in a two-dimensional frustrated ferromagnet above its saturation magnetic field Hsat for arbitrary spin S. We demonstrate that the ground state includes a magnetic vortex that is nucleated around the impurity over a finite range of magnetic field Hsat≤H≤HsatI. Upon approaching the quantum critical point at H=Hsat, the radius of the magnetic vortex diverges as the magnetic correlation length: ξ1/H-Hsat. These results are derived both for the lattice and in the continuum limit.