We investigate the spin rotational structure of magnetic skyrmions in a tetragonal polar magnet VOSe$_2$O$_5$ via polarized small-angle neutron scattering (SANS). Spin polarization analysis of the scattered neutrons reveals the cycloidal spin modulation in all the incommensurate phases at zero and non-zero magnetic field along the $c$ axis, providing unambiguous evidence for Neel-type skyrmions in this system. In the vicinity of the triangular skyrmion-lattice phase, extensive SANS measurements unravel a field-induced spin texture renouncing square skyrmion-lattice state, suggesting the relevance of thermal fluctuations to the topology of spin textures in this polar magnet.

中文翻译：

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直接观察 Néel 型 Skyrmion 承载 VOSe2O5 中的摆线自旋调制和场致跃迁

我们通过极化小角中子散射 (SANS) 研究了四方极磁体 VOSe$_2$O$_5$ 中磁性斯格明子的自旋旋转结构。散射中子的自旋极化分析揭示了沿 $c$ 轴在零和非零磁场的所有不公度相位中的摆线自旋调制，为该系统中的尼尔型斯格明子提供了明确的证据。在三角形斯格明子-晶格相附近，广泛的 SANS 测量揭示了场诱导的自旋纹理，放弃了方形斯格明子-晶格状态，表明热波动与该极磁体中自旋纹理的拓扑结构的相关性。