Schäffer Alexander F, Siegl Pia, Stier Martin, Posske Thore, Berakdar Jamal, Thorwart Michael, Wiesendanger Roland, Vedmedenko Elena Y
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, 06120, Halle (Saale), Germany.
Department of Physics, Universität Hamburg, 20355, Hamburg, Germany.
Sci Rep. 2020 Nov 23;10(1):20400. doi: 10.1038/s41598-020-77337-y.
Topologically distinct magnetic structures like skyrmions, domain walls, and the uniformly magnetized state have multiple applications in logic devices, sensors, and as bits of information. One of the most promising concepts for applying these bits is the racetrack architecture controlled by electric currents or magnetic driving fields. In state-of-the-art racetracks, these fields or currents are applied to the whole circuit. Here, we employ micromagnetic and atomistic simulations to establish a concept for racetrack memories free of global driving forces. Surprisingly, we realize that mixed sequences of topologically distinct objects can be created and propagated over far distances exclusively by local rotation of magnetization at the sample boundaries. We reveal the dependence between chirality of the rotation and the direction of propagation and define the phase space where the proposed procedure can be realized. The advantages of this approach are the exclusion of high current and field densities as well as its compatibility with an energy-efficient three-dimensional design.
诸如斯格明子、畴壁和均匀磁化状态等拓扑结构不同的磁性结构在逻辑器件、传感器以及作为信息比特等方面有多种应用。应用这些比特最有前景的概念之一是由电流或磁驱动场控制的赛道架构。在最先进的赛道中，这些场或电流被应用于整个电路。在此，我们采用微磁学和原子尺度模拟来建立一种无全局驱动力的赛道存储器概念。令人惊讶的是，我们发现拓扑结构不同的物体的混合序列可以仅通过样品边界处磁化的局部旋转来创建并远距离传播。我们揭示了旋转手性与传播方向之间的依赖关系，并定义了可以实现所提出过程的相空间。这种方法的优点是排除了高电流和场密度，以及它与节能三维设计的兼容性。
