Weakly pinned skyrmion liquid in a magnetic heterostructure
Weakly pinned skyrmion liquid in a magnetic heterostructure
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DOI：
10.1103/physrevb.106.054413
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发表时间：
2022-08
影响因子：
3.7
通讯作者：
R. Mansell;Yifan Zhou;Kassius Kohvakka;S. Ying;K. Elder;E. Granato;T. Ala‐Nissila;S. van Dijken
中科院分区：
文献类型：
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作者：
R. Mansell;Yifan Zhou;Kassius Kohvakka;S. Ying;K. Elder;E. Granato;T. Ala‐Nissila;S. van Dijken
磁Skyrmions是拓扑上不同的粒子，其热激活运动可用于实现概率计算范式。虽然已经证明了Skyrmion晶格中的固-液相变，但Skyrmion液体的行为和钉扎效应在很大程度上是未知的。在这里，我们证明了形成一个弱钉扎skyrmion液体中的磁性异质结构。通过在铁磁体/重金属界面处插入Ru楔形层，我们评估了Skyrmion动力学对Skyrmion尺寸和密度的依赖性。我们的实验表明，skyrmions的扩散是最大的稠密液体与小skyrmions。skyrmions在室温下的热运动很容易克服颗粒膜结构中钉扎位置能量的窄分布，满足概率器件架构的关键要求。微磁模拟支持了这一发现，也揭示了热激活高频的存在。
Magnetic skyrmions are topologically distinct particles whose thermally activated motion could be used to implement probabilistic computing paradigms. While solid-liquid phase transitions in skyrmion lattices have been demonstrated, the behavior of a skyrmion liquid and the effects of pinning are largely unknown. Here we demonstrate the formation of a weakly pinned skyrmion liquid in a magnetic heterostructure. By inserting a Ru wedge layer at the ferromagnet / heavy metal interface we evaluate the dependence of skyrmion dynamics on the skyrmion size and density. Our experiments demonstrate that the diffusion of skyrmions is largest in dense liquids with small skyrmions. The thermal motion of skyrmions at room temperature easily overcomes the narrow distribution of pinning site energies in the granular film structure, satisfying a key requirement of probabilistic device architectures. Micromagnetic simulations support the findings and also reveal the existence of a thermally activated high-frequency