Tunable artificial vortex ice in nanostructured superconductors with a frustrated kagome lattice of paired antidots
Tunable artificial vortex ice in nanostructured superconductors with a frustrated kagome lattice of paired antidots
复制标题
纳米结构超导体中的可调谐人工涡旋冰，具有成对解点的挫败戈薇晶格
DOI：
10.1103/physrevb.97.134506
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发表时间：
2018
影响因子：
3.7
通讯作者：
de Vondel J Van
中科院分区：
文献类型：
--
作者：
Xue C;Ge J Y;He A;Zharinov V S;Moshchalkov V V;Zhou Y H;Silhanek A V;de Vondel J Van
基于纳米结构超导体的自旋冰类似物的理论建议表明，与磁系统相比，其在探测波动和无序影响方面具有更大的灵活性。在本文中，我们通过使用扫描霍尔探针显微镜直接观察配对解毒剂的 kagome 晶格中的涡旋分布，揭示了涡旋冰系统的特殊性。理论上建议的涡旋冰分布缺乏长程有序，在半匹配场 (H-1/2) 处观察到。而且，由钉扎涡形成的涡冰状态仍然保持在2H(1)/3。这种意想不到的结果归因于在这些磁场值下引入了间隙涡旋。尽管间隙涡增加了可能的涡旋构型的数量，但清楚地表明在2H(1)/3处观察到的涡旋冰态比在H-1/2处观察到的涡旋冰态更不容易出现缺陷。此外，涡旋冰质量对晶格间距的非单调变化表明，简单地减小晶格间距无法获得高度有序的涡旋冰状态。基于实验统计，讨论了观测无缺陷涡旋冰的优化设计。对可调涡旋冰态的直接观测为探索人造冰系统中的有序-无序转变提供了新的机会。
Theoretical proposals for spin-ice analogs based on nanostructured superconductors have suggested larger flexibility for probing the effects of fluctuations and disorder than in the magnetic systems. In this paper, we unveil the particularities of a vortex ice system by direct observation of the vortex distribution in a kagome lattice of paired antidots using scanning Hall probe microscopy. The theoretically suggested vortex ice distribution, lacking long-range order, is observed at half matching field (H-1/2). Moreover, the vortex ice state formed by the pinned vortices is still preserved at 2H(1)/3. This unexpected result is attributed to the introduction of interstitial vortices at these magnetic-field values. Although the interstitial vortices increase the number of possible vortex configurations, it is clearly shown that the vortex ice state observed at 2H(1)/3 is less prone to defects than at H-1/2. In addition, the nonmonotonic variations of the vortex ice quality on the lattice spacing indicates that a highly ordered vortex ice state cannot be attained by simply reducing the lattice spacing. The optimal design to observe defect-free vortex ice is discussed based on the experimental statistics. The direct observations of a tunable vortex ice state provides new opportunities to explore the order-disorder transition in artificial ice systems.