Studies of Artificial Spin Ice at Brookhaven and Lawrence Berkeley National Laboratories

人造自旋冰是有图案的纳米磁铁阵列。他们利用纳米技术在二维模拟中重现了“自然发生的”自旋冰的许多特征——焦绿石晶体，其中稀土矩被安排在四面体顶点上以四组为一组，以加强几何挫折感。在这些人工系统中，所有参数都可以通过设计指定，并且可以使用高分辨率磁显微镜检查力矩的确切配置。因此，它们为研究热平衡内外的统计力学模型提供了令人兴奋的可能性，以一种在焦绿石系统中不可能实现的方式可视化室温下的分数化单极子激发等现象，并探索新的应用，例如使用这些单极子的“磁性”来执行神经形态计算。制造和研究这些系统需要最先进的设备。在这里，我们寻求旅行支持，使我们能够访问两个美国国家实验室的三个独特设施：布鲁克海文国家实验室（BNL）的功能纳米材料中心（CFN）和国家同步加速器光源（NSLS）以及劳伦斯伯克利国家实验室（LBNL）的先进光源（ALS），在所有这些实验室中，我们都通过竞争性同行评审赢得了研究人工自旋冰的设施时间。我们将在CFN上制造极端纳米尺度的样品，并在两个同步加速器设施上在互反（NSLS）和实空间（ALS）中研究它们。

Artificial spin ices are arrays of patterned nanomagnets. They make use of nanotechnology to reproduce many of the features found in the 'naturally-occurring' spin ices--pyrochlore crystals, in which rare earth moments are arranged meeting in groups of four at tetrahedral vertices so as to enforce geometric frustration--in a two-dimensional analog. In these artificial systems, all parameters can be specified by design and the exact configuration of the moments can be inspected using high resolution magnetic microscopy. As a result they offer exciting possibilities in studying statistical mechanical models in and out of thermal equilibrium, visualising phenomena such as fractionalised monopole excitations at room temperature in a way that is impossible in the pyrochlore systems, and exploring novel applications, such as using the 'magnetricity' of these monopoles to perform neuromorphic computing. Fabricating and studying these systems requires state-of-the-art facilities. Here we seek travel support to allow us to access three unique facilities at two US National Laboratories: the Center for Functional Nanomaterials (CFN) and the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) and the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory (LBNL), at all of which we have won facility time to study artificial spin ices through competitive peer review. We will fabricate samples at the extreme nanoscale at the CFN, and study them in reciprocal (NSLS) and real (ALS) space at the two synchrotron facilities.