N\'eel-type skyrmion lattice in tetragonal polar magnet VOSe$_2$O$_5$

TL;DR

This paper reports the discovery of a Nel-type skyrmion lattice in the tetragonal polar magnet VOSedO5, highlighting the material's potential for studying topological spin textures.

Contribution

It is the first demonstration of a Nel-type skyrmion lattice in a bulk tetragonal polar magnet, expanding understanding of skyrmion phases in such materials.

Findings

Identification of a cycloidal spin state at zero field

Observation of a Nel-type skyrmion-lattice phase under magnetic field

Detection of an incommensurate spin texture phase at lower temperatures

Abstract

Formation of the triangular skyrmion-lattice is found in a tetragonal polar magnet VOSe$_2$O$_5$. By magnetization and small-angle neutron scattering measurements on the single crystals, we identify a cycloidal spin state at zero field and a N\'eel-type skyrmion-lattice phase under a magnetic field along the polar axis. Adjacent to this phase, another magnetic phase of an incommensurate spin texture is identified at lower temperatures, tentatively assigned to a square skyrmion-lattice phase. These findings exemplify the versatile features of N\'eel-type skyrmions in bulk materials, and provide a unique occasion to explore the physics of topological spin textures in polar magnets.