Sáez Guidobeth, Díaz Pablo, Cisternas Eduardo, Vogel Eugenio E, Escrig Juan
Department of Physics, Universidad de La Frontera, Casilla 54-D, Temuco, Chile.
Center of Nanoscience and Nanotechnology (CEDENNA), 9170124, Santiago, Chile.
Sci Rep. 2021 Oct 21;11(1):20811. doi: 10.1038/s41598-021-00165-1.
A long piece of magnetic material shaped as a central cylindrical wire (diameter [Formula: see text] nm) with two wider coaxial cylindrical portions (diameter [Formula: see text] nm and thickness [Formula: see text] nm) defines a bimodulated nanowire. Micromagnetism is invoked to study the equilibrium energy of the system under the variations of the positions of the modulations along the wire. The system can be thought of as composed of five independent elements (3 segments and 2 modulations) leading to [Formula: see text] possible different magnetic configurations, which will be later simplified to 4. We investigate the stability of the configurations depending on the positions of the modulations. The relative chirality of the modulations has negligible contributions to the energy and they have no effect on the stability of the stored configuration. However, the modulations are extremely important in pinning the domain walls that lead to consider each segment as independent from the rest. A phase diagram reporting the stability of the inscribed magnetic configurations is produced. The stability of the system was then tested under the action of external magnetic fields and it was found that more than 50 mT are necessary to alter the inscribed information. The main purpose of this paper is to find whether a prototype like this can be complemented to be used as a magnetic key or to store information in the form of firmware. Present results indicate that both possibilities are feasible.
一块长磁性材料，形状为中心圆柱形导线（直径[公式：见原文]纳米），带有两个较宽的同轴圆柱形部分（直径[公式：见原文]纳米，厚度[公式：见原文]纳米），定义了一种双调制纳米线。利用微磁学研究系统在调制沿导线位置变化时的平衡能量。该系统可被视为由五个独立元素（3个段和2个调制）组成，导致[公式：见原文]种可能不同的磁构型，随后将简化为4种。我们根据调制的位置研究构型的稳定性。调制的相对手性对能量的贡献可忽略不计，且它们对存储构型的稳定性没有影响。然而，调制在固定畴壁方面极其重要，这使得每个段可被视为与其他部分独立。生成了一个报告内禀磁构型稳定性的相图。然后在外部磁场作用下测试系统的稳定性，发现需要超过50 mT的磁场才能改变内禀信息。本文的主要目的是探究这样一个原型是否可以得到补充，以用作磁钥匙或以固件形式存储信息。目前的结果表明这两种可能性都是可行的。
