Two-Dimensional Magnets in Spintronic Devices: Roles of Spin Fluctuations

自旋电子器件中的二维磁体：自旋涨落的作用

• 批准号: 2401267
• 负责人: Shufeng Zhang
• 金额: $ 36万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-05-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2401267&HistoricalAwards=false
• 关键词: Two; Dimensional; Magnets; Spintronic; Devices

In magnetic materials, intriguing quasi-particles called magnons exist. Much like the spin of an electron, magnons possess angular momentum but lack electric charge. Unlike electron currents, which incur energy losses through Joule heating, the flow of magnons, known as magnon current, offers significantly higher energy efficiency. This project undertakes a comprehensive theoretical investigation of magnon devices built upon two-dimensional (2D) magnetic materials. The primary objective is to elucidate the mechanisms underlying the generation, propagation, and detection of magnon currents within realistic 2D structures. Specifically, the project endeavors to identify material parameters capable of engendering a magnon current comparable to, or even surpassing, conventional electron spin currents. The insights gleaned from this research hold promise for the development of magnon current-driven devices characterized by substantially reduced power consumption. Additionally, the educational component of this proposal is extensive, aiming to actively involve students in hands-on research, provide training opportunities, facilitate visits to industry labs, and enhance the spintronics course curriculum. Leveraging the Principal Investigator's extensive experience spanning over two decades in teaching spintronics, this project seeks to enrich the educational landscape by immersing students in cutting-edge research endeavors.Distinctly from three-dimensional systems, two-dimensional materials demonstrate significant quantum fluctuations, critically influencing both equilibrium and non-equilibrium magnetic characteristics. Existing semiclassical models that overlook these quantum fluctuations often fall short for two-dimensional systems. The present project sets out to create novel modeling tools tailored for two-dimensional material-based spintronic devices. The objective is to assess the repercussions of spin fluctuations on spin transport properties, using experimentally observed materials as a benchmark. The specific focus is placed on a holistic theoretical approach addressing magnon conductance, spin pumping, magnon drag, and spin-charge conversion in the setting of two-dimensional heterostructures. Venturing into the granular spin models of these materials, the proposed theoretical model is to elucidate the intrinsic role of spin fluctuations in molding spintronic devices. Furthermore, the goal extends to utilizing these innovative theoretical models to meticulously analyze experimental outcomes and projecting the emergence of novel spintronic phenomena intrinsic to the pronounced quantum spin fluctuations. The research will shed light on the distinctions in two- and three-dimensional device responses to spin current and external magnetic fields. A thorough grasp of thermal and quantum fluctuation impacts – from magnetic topological states, spin Hall, and spin currents, to spin torques and magnetization reversals – can catalyze advancements in spintronic devices hinging on two-dimensional magnetic materials and provide substantial insights into low-dimensional physics.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.

在磁性材料中，存在一种称为磁振子的有趣准粒子，它与电子的自旋非常相似，具有角动量，但缺乏电荷，与通过焦耳热产生能量损失的电子流不同，磁振子的流动称为磁振子电流。 ，提供显着更高的能源效率。该项目对基于二维 (2D) 磁性材料的磁振子器件进行了全面的理论研究，主要目标是阐明产生、传播和检测的机制。该项目致力于确定能够产生与传统电子自旋电流相当甚至超过传统电子自旋电流的磁振子电流的材料参数，从这项研究中收集到的见解为磁振子电流的发展带来了希望。此外，该提案的教育部分非常广泛，旨在积极让学生参与实践研究，提供培训机会，促进参观工业实验室，并利用自旋电子学课程。首席研究员在自旋电子学教学方面拥有二十多年的丰富经验，该项目旨在通过让学生沉浸在前沿研究工作中来丰富教育景观。与三维系统不同，二维材料表现出显着的量子涨落，对两种平衡都有重要影响现有的忽略这些量子涨落的半经典模型通常无法满足二维系统的要求，目前的项目旨在创建适合基于二维材料的自旋电子器件的新型建模工具。目标是使用实验观察到的材料作为基准来评估自旋波动对自旋输运特性的影响，具体重点是解决磁振子电导、自旋泵浦、磁振子阻力和自旋电荷转换的整体理论方法。冒险研究这些材料的颗粒自旋模型，提出的理论模型是为了阐明自旋涨落在成型自旋电子器件中的内在作用。仔细分析实验结果并预测明显的量子自旋涨落所固有的新型自旋电子现象的出现，该研究将揭示二维和三维器件对自旋电流和外部磁场响应的区别。热和量子涨落影响——从磁性拓扑态、自旋霍尔和自旋电流到自旋扭矩和磁化反转——可以催化依赖于二维磁性材料的自旋电子器件的进步，并为低维提供重要的见解该奖项反映了 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进行评估，被认为值得支持。