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

人造自旋冰块是有图案的纳米磁铁阵列。他们利用纳米技术以二维模拟的方式重现了自然形成的自旋冰--烧绿石晶体中的许多特征，在这种晶体中，稀土矩在四面体的顶点上以四个一组的形式相遇，以加强几何上的挫折感。在这些人工系统中，所有参数都可以通过设计来指定，并且可以使用高分辨率磁性显微镜来检查力矩的准确构形。因此，它们在研究热平衡内外的统计力学模型方面提供了令人兴奋的可能性，以焦绿石系统中不可能的方式可视化了室温下的单极激发等现象，并探索了新的应用，例如利用这些单极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施。在这里，我们寻求差旅支持，让我们能够访问两个美国国家实验室的三个独特的设施：布鲁克海文国家实验室(BNL)的功能纳米材料中心(CFN)和国家同步辐射光源(NSLS)，以及劳伦斯伯克利国家实验室(LBNL)的先进光源(ALS)，在所有这些设施中，我们都赢得了通过竞争性同行审查来研究人造自旋冰块的设施时间。我们将在CFN制造极纳米尺度的样品，并在两个同步加速器设施的倒易(NSLS)和真实(ALS)空间进行研究。

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.