New Physics in Artificial Spin Ice via Materials Innovation

非技术摘要磁性材料在技术上极其重要，尺寸在纳米范围内的磁体在一系列应用中尤其重要，例如硬盘驱动器。这种微小的纳米磁铁的基本物理原理也令人兴奋，因为它们的集合显示了在任何其他物理系统中都无法观察到的行为，并且可以非常精确地控制。在某些精心设计的阵列中，这些纳米磁体的集合被称为“人造自旋冰”，因为它们与冰中的水分子有一些共同的潜在物理意义。这项研究计划研究由精心挑选的材料组成的人造自旋冰，这些材料会导致一系列不寻常的行为，否则这些行为是无法获得的，一旦被探索和理解，可能会产生重大的技术影响。虽然这一领域的绝大多数先前研究只使用简单的磁性材料，但这项工作将引入更多奇异的材料来访问特定的、不寻常的和潜在有用的物理。除了与可能的技术联系外，这项研究还将对本科生和研究生的教育做出重大贡献，研究努力将为代表全国更大的研究生态系统的研究人员的工作提供信息。技术摘要该研究计划将通过两名具有高度互补性专业知识的研究人员在材料制造和表征以及磁性测量方面的合作，通过战略选择的创新铁磁材料制造阵列，显著扩展可以在人造自旋冰中探测的物理。这项研究将集中在三个方面：1.由指向结构平面外的磁矩实现的新的人造自旋冰物理，探索无法用面内磁矩访问的合作现象。2.强变温磁化区的人工自旋冰行为和超顺磁性。3.通过连通的人造自旋冰网络的紧急物质诱导的电子输运现象。这些研究成果可能在新的计算范式和磁悬浮学中具有技术相关性。本科生和研究生研究人员将深入参与研究工作，并将获得一系列技能，以促进他们的专业发展。这两位调查人员还将利用他们参与的各种活动来进一步支持国家研究社区。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical AbstractMagnetic materials are extremely important technologically, and magnets that have size scale in the range of nanometers are especially important in a range of applications, such as hard disk drives. The fundamental physics of such tiny “nanomagnets” is also exciting, because collections of them show behavior that cannot be observed in any other physical system and can be controlled very precisely. Collections of these nanomagnets in certain carefully designed arrays are called “artificial spin ice” because they share some underlying physics with water molecules in ice. This research program studies such artificial spin ice composed of carefully chosen materials that result in a wide range of unusual behavior that would otherwise be inaccessible and could have significant technological implications once explored and understood. While the vast majority of prior research in this area uses only simple magnetic materials, this work will introduce more exotic materials to access specific, unusual, and potentially useful physics. Aside from connections to possible technologies, the research will also contribute substantially to the education of both undergraduate and graduate students, and the research efforts will inform the investigators’ work on behalf of the larger research ecosystem in the nation.Technical Abstract The research program will significantly expand the physics that can be probed in artificial spin ice by fabricating arrays from strategically chosen, innovative ferromagnetic materials through a collaboration between two investigators with highly complementary expertise, in materials fabrication and characterization, and magnetic measurements. The research will focus on three thrusts: 1. New artificial spin ice physics enabled by magnetic moments that point out of the plane of the structures, exploring cooperative phenomena that are inaccessible with in-plane moments. 2. Artificial spin ice behavior and superparamagnetism in the regime of strongly-temperature-dependent magnetization. 3. Emergent materials-induced electronic transport phenomena through networks of connected artificial spin ice. The research findings may have technological relevance in new computing paradigms and in magnonics. Undergraduate and graduate student researchers will be deeply involved in the research efforts and will gain a range of skills to advance their professional development. Both investigators will also leverage their involvement in various activities to further support the national research community.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.