Collaborative Research: Ferrimagnetic Insulator Based Bilayers for Interface-Driven Topological Spin Textures

数据无处不在。它是由我们随身携带的设备、家庭和汽车中的嵌入式电子产品以及功能日益强大的计算机和服务器加速产生的。这需要大量的能量来创建、存储和传输数据。需要在数据存储和处理方面进行创新，而基于半导体的传统电子设备无法胜任这一任务。自旋电子学将电子学与自旋结合起来，自旋是基本粒子的固有属性。该项目的目标是为自旋电子学开发一种新的材料平台，允许新型设备用于节能存储和计算。研究人员将集中在异质结构组成的磁性薄膜与相邻的金属层。研究人员将生长高质量的双层膜，表征原子级尖锐界面的相互作用，并优化其应用性能。这项基础研究可能会导致便携式非易失性存储器设备的尺寸更小，密度更高，比目前可用的更节能。本科生和研究生将接受培训，在关键的科学和技术领域工作，以支持创新驱动的经济。两所研究所将共同教授一门自旋电子学课程，并在两所院校开设一门“物理学中的人类”课程。技术说明磁skyrmions是未来超高密度、高能效磁存储器件的一个有希望的候选者。它们表现出强大的拓扑稳定性，具有纳米尺寸，并且需要低电流来写入，擦除和传输它们。为了使基于skyrmion的下一代磁存储技术成为现实，需要彻底了解磁性双层界面处的基本相互作用，包括交换耦合，Dzyaloshinskiii-Moriya相互作用和磁各向异性。这些相互作用需要明智地调整，以在室温下容纳纳米大小的skyrmions。为了实现这一目标，PI进行了一项关于磁性石榴石双层作为节能自旋电子材料的合作研究项目。该团队将外延薄膜生长与先进的光谱学方法相结合，旨在实现以下目标：（i）通过生长和光谱表征的快速反馈回路建立结构-性能相关性;（ii）优化具有理想特性的skyrmions和创纪录速度的手性畴壁运动的双层膜;以及（iii）探索由外延亚铁磁绝缘膜和货车德瓦尔斯覆盖层组成的新型双层。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。

NON-TECHNICAL DESCRIPTIONData is everywhere. It is generated at an accelerating pace by the devices we carry with us, embedded electronics in our homes and cars, and increasingly powerful computers and servers. This requires an enormous amount of energy for data creation, storage, and transmission. Innovations in data storage and processing are needed, and conventional electronics based on semiconductors are not equal to the task. Spintronics combines electronics with spin, an intrinsic property of elementary particles. The goal of this project is to develop a new material platform for spintronics, allowing new types of devices for energy-efficient memory and computing. Investigators will focus on heterostructures consisting of ultrathin magnetic films with an adjacent metallic layer. Investigators will grow high-quality bilayer films, characterize interactions at the atomically sharp interfaces, and optimize their properties for use in applications. This fundamental research could lead to portable, nonvolatile memory devices that are smaller in size, higher in density, and more energy efficient than those currently available. Undergraduate and graduate students will be trained to work in the critical science and technology fields to support an innovation-driven economy. The PIs will jointly teach a course on spintronics as well as expand a course on “Being Human in Physics” to both of their institutions.TECHNICAL DESCRIPTIONMagnetic skyrmions are a promising candidate for future ultrahigh-density, high energy efficiency magnetic memory devices. They exhibit robust topological stability, have nanoscale sizes, and a low electrical current is required to write, erase, and transport them. In order for skyrmion-based next-generation magnetic memory technology to become a reality, the fundamental interactions at the interfaces of magnetic bilayers need to be thoroughly understood, including exchange coupling, Dzyaloshinskii-Moriya interaction, and magnetic anisotropy. These interactions need to be judiciously tuned to host nanometer-sized skyrmions at room temperature. To achieve this goal, the PIs pursue a collaborative research project on ultrathin magnetic garnet-based bilayers as energy-efficient spintronic materials. The team integrates epitaxial film growth with advanced spectroscopy methods and aims to achieve the following goals: (i) establishing the structure-property correlation via a rapid feedback loop of growth and spectroscopy characterization; (ii) optimizing bilayers for skyrmions with desirable characteristics and chiral domain wall motions with record-breaking velocity; and (iii) exploring a new class of bilayers consisting of an epitaxial ferrimagnetic insulator film and a van der Waals overlayer.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.