In this study, we measure the magnetic field and temperature variations of the magnetization \(M(H,T)\) of the cubic chiral compound EuPtSi and extensively investigate the magnetic phase transitions in a wide temperature range down to 60 mK. The incommensurate–commensurate transition at \(T_{\text{N}}^{*} \simeq 2.5\) K in the helical state, which has not been observed in transport or thermodynamic measurements, is exclusively detected in M(T) for H || 〈111〉. \(T_{\text{N}}^{*}\) shows a rapid decrease in H. For H || [100] and [111], M(H) at T < 100 mK showed that the helical q vectors are depinned from the preferred orientations at \(H \gtrsim 10\) kOe and gradually rotate toward the field directions as H increases. The skyrmion lattice phase (A-phase) field-induced in H || 〈111〉 only above 0.4 K in equilibrium conditions can be created at 60 mK under field cooling, with a sharp tilted plateau structure developing in M(H) of the A-phase. A similar metastable state is also created below 100 mK for the A′ phase induced by H || 〈100〉 at \(T \gtrsim 0.3\) K in equilibrium conditions. The magnetic phase diagrams established for the three directions [111], [110], and [100] are highly anisotropic and discussed herein on the basis of the q vectors rather strongly pinned to the lattice and transform under the lattice symmetry operations.

中文翻译：

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磁化测量研究4f Skyrmion化合物EuPtSi的磁相变

在这项研究中，我们测量了磁场和磁化强度的温度变化 \（M（H，T）\）立方手性化合物EuPtSi的研究，并广泛研究了低至60 mK的宽温度范围内的磁性相变。不相称-相称过渡\（T _ {\ text {N}} ^ {*} \ simeq 2.5 \）螺旋态的K在运输或热力学测量中未发现，仅在M（T）中检测到H ||。〈111〉。\（T _ {\ text {N}} ^ {*} \）显示H迅速降低。对于H || [100]和[111]，在T <100 mK时的M（H）表明，螺旋q向量从在\（H \ gtrsim 10 \）kOe随H的增加逐渐向着场方向旋转。H ||场致的天敌离子晶格相（A相）〈111〉在场冷却下在60 mK时只能在平衡条件下产生高于0.4 K的值，并且在A相的M（H）处形成陡峭的倾斜平台结构。在100 mK以下，由H ||诱导的A'相也会产生类似的亚稳态。〈100〉\（T \ gtrsim 0.3 \）平衡条件下的K。为三个方向[111]，[110]和[100]建立的磁相图是高度各向异性的，在此基于q矢量进行了讨论，这些矢量相当牢固地固定在晶格上，并在晶格对称操作下进行转换。