GOALI: Novel Magnetic Structures for Energy-Efficient Spin-Based Electronic Devices

翻译后摘要：基于自旋的电子，通常被称为自旋电子学，利用自旋的电子，除了它的电荷，以提供更多的功能和节能的设备。近年来，自旋转移矩的概念得到了广泛的关注，因为它提供了高密度的计算机存储器和基于自旋的逻辑器件。然而，现有的电子自旋扭矩效率低，并且因此需要高电流用于装置中的信息存储。来自亚拉巴马大学和IBM研究中心的大学-工业团队的这一提议提出了对新型自旋电子器件结构的研究，该结构利用了一种潜在的非常有效的产生自旋转移扭矩的方法-通过磁性多层结构中的温差产生的自旋电流。了解界面处的自旋转移特性并成功演示所提出的概念可以大大提高自旋器件的能效，从而开辟新的应用。拟议的项目需要多学科的努力，这将对科学知识、教育推广和基础设施作出重大贡献。项目人员将在与拟议研究有关的若干现行教育和外联活动中发挥关键作用。其中包括与当地学校合作，以促进高中学生参与研究，公众图尔斯参观和示范。拟议的项目将调查一个新的自旋电子器件的概念，解决目前的自旋转移扭矩器件所需的高写入电流的问题。项目目标背后的物理原理是基于最近的理论预测，该预测概述了提高超薄磁性层切换所需的自旋扭矩效率的热路线。关键材料是一种磁性绝缘体，当热激发时会产生自旋波（或磁振子）。当磁振子将自旋信息传递给相邻导电间隔层中的导电电子时，净结果是自旋极化电流的放大。所提出的热磁方法有可能实现一至两个数量级的更大的量子产率在自旋转移力矩器件。这项研究合作将从根本上开发新的知识和理解，从理论上预测的热自旋扭矩效应，从氧化物基磁性绝缘体内产生的磁振子。应进行候选异质结构中自旋力矩和自旋泵行为的基础研究。铁磁共振，磁光技术，和图案化的纳米结构的磁显微镜应阐明热自旋转移扭矩效应和量化的热自旋电流转换效率。独特的合成策略，应追求利用低温生长工艺的磁性尖晶石氧化物和石榴石薄膜，这是预计将是至关重要的整合不同的一套材料。

Abstract:Spin-based electronics, commonly referred to as spintronics, exploits the spin of the electron in addition to its charge to provide more functional and energy-efficient devices. In recent years the concept of spin-transfer torque has gained much attention since it offers high density in computer memory and logic devices based on spintonics. However, existing electronic spin-torque efficiency is low, and, as a result, requires high current for information storage in devices. This proposal from the university-industry team at the University of Alabama and IBM Research Center puts forward an investigation into novel spin-based electronic device structures that utilizes a potentially extremely efficient means of generating spin-transfer torque - by spin currents generated by a temperature difference in magnetic multilayer structures. Understanding the spin transfer properties at the interfaces and successful demonstration of the proposed concept can lead to considerable improvement in the energy efficiency of spin-based devices that will open up new applications. The proposed project requires a multidisciplinary effort that will make significant contributions to scientific knowledge, education outreach and infrastructure. Project personnel will play a key role in several ongoing education and outreach activities related to the proposed research. These include collaboration with local schools to facilitate participation by high school students in research, public tours and demonstrations.The proposed project will investigate a novel spintronic device concept that addresses the issue of high write currents required for present spin-transfer torque devices. The physical principle behind the project goals is based on a recent theoretical prediction that outlines a thermal route of enhancing the spin torque efficiency required to switch an ultra-thin magnetic layer. The key material is a magnetic insulator which generates spin waves (or magnons) when thermally excited. The net result is amplification in the spin-polarized current when the magnons transfer spin information to the conduction electrons in an adjoining conducting spacer layer. The proposed thermagnonic method has the potential for achieving one to two orders-of-magnitude greater quantum yield in spin-transfer torque devices. The research collaboration will develop fundamentally new knowledge and understanding of the theoretically predicted thermal spin-torque effect from magnons generated within oxide-based magnetic insulators. Fundamental investigations of spin-torque and spin-pumping behavior in candidate heterostructures shall be undertaken. Ferromagnetic resonance, magneto-optic techniques, and magnetic microscopy of patterned nanostructures shall elucidate the thermal spin-transfer torque effect and quantify the thermal-to-spin-current conversion efficiency. Unique synthetic strategies shall be pursued that exploit low temperature growth processes for magnetic spinel oxide and garnet films, which is expected to be crucial for integrating a disparate set of materials.