Skyrmion magnetic textures stabilized by chiral interactions in magnetic nanosystems

在拟议的研究中，我们从理论上研究了磁性纳米层中特定的粒子状局域结构（Skyrmions）。这些新的孤子结构在我们早期的研究中已经被预测存在。磁性Skyrmions是具有纳米尺度和固定旋转方向（手性）的内在稳定的局域非均匀性。由于反转对称性破缺，手性相互作用是稳定磁性Skyrmionic态的基本因素。众所周知，这些相互作用在纳米级磁性系统中普遍存在，例如磁性层，这是由于在表面处的反转对称性破缺。本项目的主要目标是发展一个关于Skyrmion态的唯象理论，并对Skyrmion态在外加磁场、外加应力和温度变化的影响下的形成、演化和转变的物理过程有一个基本的认识。计算的结果将被应用于分析的磁化过程中的磁性纳米层，纳米盘，和低对称性磁性晶体的内在磁相互作用或表面诱导的手性有利于形成Skyrmions的薄层。我们的研究结果将有助于识别和控制纳米磁性的手征效应。作为我们的主要工具将是唯象理论的磁性，其结果将建立有用的物理连接磁性和其他非线性凝聚态系统，如铁电和多铁性材料或手性液晶。

In the proposed research we study theoretically specific particle-like localized structures (Skyrmions) in magnetic nanolayers. These novel solitonic structures have been predicted to exist in our earlier studies. Magnetic Skyrmions are intrinsically stable localized inhomogeneities with the size of nanometers and with a fixed rotation sense (chirality). Essential ingredient for the stabilization of magnetic Skyrmionic states are chiral interactions due to broken inversion symmetry. It is known that these interactions are ubiquitous in nanoscale magnetic systems such as ultrathin layers, due to the broken inversion symmetry at the surfaces. Therefore, it is expected that Skyrmion states can be realized in nanoscale magnetic systems.The main goal of the project is to develop a consistent phenomenological theory of Skyrmions in nanolayers and obtain a fundamental understanding of physical processes of their formation, evolution and transformation under the influence of applied magnetic fields, extemal stresses and variation of temperature. The results of calculations will be applied to analyze the magnetization processes in magnetic nanolayers, nanodisks, and thin layers of low-symmetry magnetic crystals where intrinsic magnetic interactions or surface-induced chirality favour the formation of Skyrmions. Our findings will be instrumental to identify and control chirality effects in nanomagnetism. As our main tool will be phenomenological theory of magnetism, the results will establish useful physical connections between magnetic and other nonlinear condensed matter systems such as ferroelectric and multiferroic materials or chiral liquid crystals.