Voltage-based switching of memory elements based-on spin dephasing, diffusion and switching in ferrimagnetic metals

基于亚铁磁金属自旋相移、扩散和切换的存储元件电压切换

• 批准号: 2116991
• 负责人: Barry Zink
• 金额: $ 35.99万
• 依托单位: University of Denver
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2116991&HistoricalAwards=false
• 关键词: Voltage; based; switching; memory; elements

Our economy and society rely heavily on information technology, which consumes an ever-growing amount of energy to process and store the world’s information. This makes energy-efficient, non-volatile memory systems a critical goal for future computers. Magnets, where information is encoded in bits typically formed from ferromagnetic materials with “north” and “south” poles with very much reduced size, currently store a huge amount of information. However, these memory systems rely on magnetic fields to manipulate the poles, giving a technology with non-volatile storage but limited size and energy efficiency. This project aims to achieve a low-current, based on materials with properties of antiferromagnets and ferromagnets, called a ferrimagnet by using all electrical means of manipulating nanoscale non-volatile magnetic memory. A ferrimagnet has vanishing magnetization at a certain temperature which can be shifted with carefully engineered applied electric field. This project will provide fundamental scientific knowledge and demonstration of this principle, for the fabrication of energy efficient, non-volatile, nanoscale magnetic memory and switching devices. The project will involve graduate and undergraduate students training and outreach activities involving collaboration with the student physics club, online spintronics seminar series and brown bag seminars. This project focuses on ferrimagnetic metal alloys and bilayers, with the overall goal of demonstrating voltage-based switching of memory elements using a detection scheme based on the anomalous Hall effect, and of spin transport sensors such as non-local spin valves. One specific focus is on a design of a new experiment to measure both the spin dephasing length and the spin diffusion length in ferrimagnetic metals. These measurements for a single material, will provide critical information for a range of spintronic systems and devices. The project will also explore voltage manipulation via electrolytic gating using an ionic gel. The project explores temperature-driven switching of the ferrimagnet as a first step toward eventual voltage-gated switching, which could also prove useful for applications in sensing. Research activities will involve characterization and development of ferrimagnetic metals, including SQUID magnetometry and thermoelectric and thermal conductivity measurements using unique micro- and nanomachined measurement tools. The project has four main thrusts: (1) Developing, optimizing, and characterizing materials for ferrimagnetic spintronics, (2) Measuring the spin dephasing and diffusion lengths in ferrimagnetic metals, (3) Using a ferrimagnet to Realize Voltage-Driven Deterministic Magnetic Switching, and 4) Tuning spin direction in a ferrimagnetic non local spin valve.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.

我们的经济和社会在很大程度上依赖信息技术，而信息技术处理和存储世界信息所消耗的能源越来越多。 这使得节能、非易失性存储系统成为未来计算机的关键目标。 磁铁，其中信息被编码在比特中，通常由具有“北”极和“南”极的铁磁材料形成，具有非常小的尺寸，目前存储大量的信息。 然而，这些存储器系统依赖于磁场来操纵磁极，提供了一种具有非易失性存储但尺寸和能效有限的技术。 该项目旨在实现一种低电流，基于具有反铁磁体和铁磁体性质的材料，称为亚铁磁体，通过使用操纵纳米级非易失性磁存储器的所有电气手段。 亚铁磁体在一定温度下具有消失的磁化强度，其可以通过仔细设计的施加电场来移位。 该项目将为制造节能、非易失性、纳米级磁存储器和开关器件提供基本的科学知识和这一原理的演示。 该项目将涉及研究生和本科生的培训和推广活动，涉及与学生物理俱乐部，在线自旋电子学研讨会系列和棕色袋研讨会合作。该项目的重点是亚铁磁金属合金和双层，总体目标是使用基于异常霍尔效应的检测方案演示基于电压的存储元件开关，以及自旋输运传感器，如非本地自旋阀。一个具体的重点是设计一个新的实验来测量自旋退相长度和自旋扩散长度在亚铁磁金属。这些对单一材料的测量将为一系列自旋电子系统和设备提供关键信息。该项目还将探索使用离子凝胶通过电解门控进行电压操纵。该项目探索了亚铁磁体的温度驱动开关，作为最终电压门控开关的第一步，这也可能被证明对传感应用有用。研究活动将涉及亚铁磁金属的表征和开发，包括SQUID磁力测量以及使用独特的微和纳米机械测量工具进行的热电和热导率测量。 该项目有四个主要目标：（1）开发、优化和表征亚铁磁自旋电子学材料，（2）测量亚铁磁金属中的自旋退相和扩散长度，（3）使用亚铁磁体实现电压驱动的确定性磁开关，和4）亚铁磁非定域自旋阀中自旋方向的调谐。该奖项反映了NSF的法定使命，并通过评估被认为值得支持使用基金会的知识价值和更广泛的影响审查标准。