Large vortex state in ferromagnetic disks.
Large vortex state in ferromagnetic disks.
复制标题
铁磁盘中的大涡旋状态。
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
K. Metlov
中科院分区：
文献类型：
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作者：
K. Metlov
软铁磁纳米盘中的磁涡旋已经被广泛研究了至少几十年，因为它们的基本（作为基本粒子的场论模型的“活”宏观实现）以及高速高密度功率无关信息存储的应用价值。结果表明，在不同交换长度的纳米铁磁圆盘中，存在另一种稳定的涡旋态，其核轮廓随厚度变化较大。它的能量进行了数值计算（在Magnetism@home分布式计算项目的框架内），其稳定性进行了分析研究，这使得它可以绘制在磁相图上。在某些几何形状的圆柱体中，大涡旋与经典涡旋一样存在，同时被能量屏障隔开，可以通过调整铁磁盘的几何形状和材料来控制。它们可以成为磁信息存储的优秀候选者，不仅因为所得到的磁盘尺寸是最小的，能够支持磁涡旋，而且还因为它是所有其他已知的磁性纳米柱亚稳态中最接近经典涡旋态的。这意味着，基于这两种类型的磁涡流之间的切换的存储器可能会实现最高的切换速率。
Magnetic vortices in soft ferromagnetic nano-disks have been extensively studied for at least several decades both for their fundamental (as a "live" macroscopic realization of a field theory model of an elementary particle) as well as applied value for high-speed high-density power-independent information storage. Here it is shown that there is another stable vortex state with large thickness-dependent core profile in nano-scale ferromagnetic disks of several exchange lengths in size. Its energy is computed numerically (in the framework of Magnetism@home distributed computing project) and its stability is studied analytically, which allows to plot it on magnetic phase diagram. In cylinders of certain geometries large vortices exist on par with classical ones, while being separated by an energy barrier, controllable by tuning the geometry and material of ferromagnetic disk. They can be an excellent candidate for magnetic information storage not only because the resulting disk sizes are among the smallest, able to support magnetic vortices, but also because it is the closest to the classical vortex state of all other known metastable states of magnetic nano-cylinder. It means that memory, based on switching between these two types of magnetic vortices, may, potentially, achieve the highest possible rate of switching.