斯格明子边界效应和运动学特征的研究

发布时间：2018-04-21 11:08

本文选题：斯格明子 + 边界效应　；参考：《四川师范大学》2017年硕士论文

【摘要】：磁性材料是一种古老且具有旺盛生命力的功能材料。作为磁性材料的一个重要的分支,磁存储材料广泛地应用于日常生活中。目前,斯格明子(skyrmion)是磁存储材料的新星,它有望成为只需极小电流就可驱动的未来数据存储器和逻辑设备的基本存储单元。其中,以斯格明子为基础的赛道内存因非易失性、高效节能、超高存储密度和极小的欧姆热等优点引起了国内外普遍关注。本论文利用三维微磁学模拟软件OOMMF(the Object-Oriented MicroMagnetic Framework),计算了在受限系统中,边界对斯格明子成核情况的影响以及在周期性赛道上斯格明子的运动学特征,主要的研究结果如下:1.只有当自旋极化电流注入区域和铁磁纳米赛道端部之间的距离超过某一阈值(临界距离dc)时,稳定的斯格明子才能通过注入垂直自旋极化电流而产生;当距离未达到临界距离dc时,将会产生除斯格明子之外的其他自旋结构,这些自旋结构在电流的驱动下最终都会湮灭;不同的自旋结构所对应的能量也会不同,但是斯格明子态的能量最低。只有合适的电流密度、磁性参数和材料参数下才能成功地产生斯格明子。形成单个和同时形成多个斯格明子的临界距离dc是相同的。2.在周期性赛道上斯格明子的运动学特征:进一步证实了边缘高磁晶各向异性材料可有效地抑制由马格努斯力引起的横向漂移;赛道的窄部和宽部分别对应于能量曲线的峰值和谷值,并且得证于斯格明子的驰豫过程;只有合适的驱动电流密度和赛道窄部才能使斯格明子通过所有的窄部且不湮灭。
[Abstract]:Magnetic material is an old functional material with exuberant vitality. As an important branch of magnetic materials, magnetic storage materials are widely used in daily life. At present, Skyrmion is a new star of magnetic storage material, which is expected to be the basic memory cell of future data memory and logic devices which can be driven by only minimal current. Among them, the track memory based on Schumminon has attracted widespread attention at home and abroad for its advantages of non-volatile, efficient energy saving, ultra-high storage density and minimal ohmic heat. In this paper, the effect of boundary on the nucleation of the Schumminon and the kinematics characteristics of the Schumminon on the periodic track are calculated by using the three-dimensional micromagnetic simulation software OOMMF(the Object-Oriented MicroMagnetic Framework. The main results are as follows: 1. Only when the distance between the spin-polarized current injection region and the end of the ferromagnetic nanotrack exceeds a certain threshold (critical distance DC), the stable Spinemminon can be produced by injecting the vertical spin polarization current. When the distance does not reach the critical distance DC, there will be spin structures other than the Schumminon, which will eventually be annihilated by the current, and the energy of the different spin structures will be different. But the energy of the Schumminon state is the lowest. Only when the current density, magnetic parameters and material parameters are suitable, can the Schumminon be produced successfully. The critical distance DC for forming a single and simultaneous Sgrimings is the same as. 2. 2. The kinematic characteristics of the Schumminon on the periodic track: it is further proved that the edge high magnetic crystal anisotropic material can effectively suppress the transverse drift caused by the Magnus force; The narrow part and the wide part of the track correspond to the peak and valley value of the energy curve, respectively, and the relaxation process of the Schumminon is proved. Only the proper driving current density and the narrow part of the track can make the Schumminon pass through all the narrow parts without annihilation.
【学位授予单位】：四川师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O482.5

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