Direct visualization of memory effects in artificial spin ice
Direct visualization of memory effects in artificial spin ice
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DOI：
10.1103/physrevb.92.104417
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发表时间：
2015-09-16
影响因子：
3.7
通讯作者：
Schiffer, Peter
中科院分区：
文献类型：
--
作者：
Gilbert, Ian;Chern, Gia-Wei;Schiffer, Peter
我们的实验表明，阵列的相互作用纳米级铁磁岛，被称为人工自旋冰，开发可重复的微观循环施加磁场后。这种记忆效应的开始由相对于阵列介电性的施加场的强度确定。具体地，当施加的场强几乎完全等于阵列的双折射率时，在阵列实现几乎完全可重复的微状态之前需要几个训练周期，而当施加的场强比阵列的双折射率强或弱时，在第一次小循环之后实现可重复的微状态。我们通过实验和模拟表明，人工自旋冰所表现出的这种记忆是由于棘轮效应的相互作用，磁荷缺陷的岛屿时刻配置和网络的复杂性的字符串的反转的时刻，在磁化反转过程中形成。
We experimentally demonstrate that arrays of interacting nanoscale ferromagnetic islands, known as artificial spin ice, develop reproducible microstates upon cycling an applied magnetic field. The onset of this memory effect is determined by the strength of the applied field relative to the array coercivity. Specifically, when the applied field strength is almost exactly equal to the array coercivity, several training cycles are required before the array achieves a nearly completely repeatable microstate, whereas when the applied field strength is stronger or weaker than the array coercivity, a repeatable microstate is achieved after the first minor loop. We show through experiment and simulation that this memory exhibited by artificial spin ice is due to a ratchet effect on interacting, magnetically charged defects in the island moment configuration and to the complexity of the network of strings of reversed moments that forms during magnetization reversal.