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arXiv 1406.2177cond-mat.mes-hallcond-mat.str-el
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非中心对称磁体中的手征Skyrmion态

Chiral skyrmion states in non-centrosymmetric magnets

A. O. Leonov

摘要:

非中心对称磁性晶体中存在手性Skyrmion态,这是由于不对称交换Dzyaloshinskiii-Moriya相互作用破坏了均匀的磁性状态,通常导致扭曲的无公度磁性自旋结构。最近,在具有非中心对称立方B20晶体结构的手征螺旋磁体的磁性层中观察到了Skyrmion晶格和自由Skyrmion。这些态的稳定性和它们的变换性质令人印象深刻地说明了理论预测的这些手性二维局域自旋态的孤子性质。本文主要研究了六角Skyrmion晶格中立方螺旋磁网的数值严格解。它证明和扩展以前的近似解决方案,使用圆细胞近似(CCA)的计算的自由能的Skyrmion晶格。本文的理论结果提供了一个全面的描述skyrmion晶格演化中施加的磁场和/或在存在单轴,立方和交换各向异性。本文将磁化强度固定模量M=常数的低温唯象理论应用于手征磁体的磁态。

英文摘要:

Chiral skyrmion states exist in non - centrosymmetric magnetic crystals as a consequence of the asymmetric exchange Dzyaloshinskii-Moriya interactions that destroy the homogeneous magnetic state and generally lead to twisted incommensurate magnetic spin-structures. Recently, skyrmion lattices and free skyrmions in magnetic layers of the chiral helimagnets with the noncentrosymmetric cubic B20 crystal structure have been observed. The stabilization of these states and their transformation properties impressively illustrate the theoretically predicted solitonic nature of these chiral two-dimensionally localized spin-states. This paper is mainly devoted to numerically rigorous solutions of hexagonal skyrmion lattices for cubic helimagnets. It justifies and extends previous approximate solutions that used a circular cell approximation (CCA) for the calculation of the free energy of skyrmion lattices. The theoretical results of the present paper provide a comprehensive description of skyrmion lattice evolution in an applied magnetic field and/or in the presence of uniaxial, cubic, and exchange anisotropy. The low-temperature phenomenological theory with fixed modulus of magnetization, M=const, is applied to the magnetic states in chiral magnets.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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