Exploring hyper-cubic energy landscapes in thermally active finite artificial spin-ice systems
Exploring hyper-cubic energy landscapes in thermally active finite artificial spin-ice systems
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DOI：
10.1038/nphys2613
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发表时间：
2013-06-01
期刊：
影响因子：
19.6
通讯作者：
Heyderman, L. J.
中科院分区：
文献类型：
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作者：
Farhan, A.;Derlet, P. M.;Heyderman, L. J.
由偶极耦合单畴磁体阵列构建的二维人造自旋冰系统提供了一种实验途径来研究挫败物理以及随系统尺寸呈指数增长的相应简并性。然而，到目前为止，此类系统仍然主要冻结在磁铁的居里温度以下，无法通过热波动探索其势能景观。在这里，我们演示了热活性有限人造自旋冰系统的创建以及实时和空间磁波动的观察。我们表明，随后的磁化动力学可以从潜在的偶极能量景观中完全理解，并证明能量规模和景观的复杂性都会影响观察到的构型变化的时间和空间性质。这项工作为热感应磁弛豫过程的原位研究铺平了道路，并为扩展二维人造自旋冰系统中的最低能量状态提供了一条受控路线。
Two-dimensional artificial spin-ice systems constructed from arrays of dipolar coupled monodomain magnets offer an experimental route to study the physics of frustration and a corresponding degeneracy that grows exponentially with system size. However, so far, such systems remain mainly frozen below their magnet's Curie temperature, unable to explore their potential-energy landscape through thermal fluctuations. Here we demonstrate the creation of thermally active finite artificial spin-ice systems and the observation of magnetic fluctuations in real time and space. We show that the subsequent magnetization dynamics can be entirely understood from the underlying dipolar energy landscape, and demonstrate that both the energy scale and the complexity of the landscape affect the temporal and spatial nature of the observed configurational changes. This work paves the way for the in situ study of thermally induced magnetic relaxation processes and delivers a controlled route to the lowest-energy state in extended two-dimensional artificial spin-ice systems.