Over the past decade the family of chiral noncollinear spin textures has continued to expand with the observation in metallic compounds of Bloch-like skyrmions in several B20 compounds, and antiskyrmions in a tetragonal inverse Heusler. Néel like skyrmions in bulk crystals with broken inversion symmetry have recently been seen in two distinct nonmetallic compounds, GaV4 S8 and VOSe2 O5 at low temperatures (below ≈13 K) only. Here, the first observation of bulk Néel skyrmions in a metallic compound PtMnGa and, moreover, at high temperatures up to ≈220 K is reported. Lorentz transmission electron microscopy reveals the chiral Néel character of the skyrmions. A strong variation is reported of the size of the skyrmions on the thickness of the lamella in which they are confined, varying by a factor of 7 as the thickness is varied from ≈90 nm to ≈4 µm. Moreover, the skyrmions are highly robust to in-plane magnetic fields and can be stabilized in a zero magnetic field using suitable field-cooling protocols over a very broad temperature range to as low as 5 K. These properties, together with the possibility of manipulating skyrmions in metallic PtMnGa via current induced spin-orbit torques, make them extremely exciting for future spintronic applications.

中文翻译：

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金属PtMnGa中强健的NéelSkyrmions的观察。

在过去的十年中，随着在几种B20化合物中的Bloch状Skyrmion的金属化合物以及在四边形逆Heusler中的抗Skyrmion的观察，手性非共线自旋织构的家族不断扩展。最近，在低温（约13 K以下）的两种不同的非金属化合物GaV4 S8和VOSe2 O5中发现了具有破碎的反转对称性的块状晶体中的Néel状的Skyrmion。在这里，首次观察到金属化合物PtMnGa中的大量Néelskyrmions，此外，还观察到了高达≈220K的高温。洛伦兹透射电子显微镜揭示了天敌的手性奈尔特征。据报道，在密封的薄片的厚度上，Skyrmion的尺寸有很大的变化，当厚度从≈90nm改变到≈4µm时变化了7倍。