Magnetic vortex as a ground state for micron-scale antiferromagnetic samples

Here we consider micron-sized samples with any axisymmetric body shape and made with a canted antiferromagnet, like hematite or iron borate. We find that its ground state can be a magnetic vortex with a topologically nontrivial distribution of the sublattice magnetization (l) over right arrow and planar coreless vortexlike structure for the net magnetization (M) over right arrow. For antiferromagnetic samples in the vortex state, in addition to low-frequency modes, we find high-frequency modes with frequencies over the range of hundreds of gigahertz, including a mode localized in a region of radius similar to 30-40 nm near the vortex core.