Magnetic Skyrmion for Nonvolatile Low-Power Spin-Orbitronics Applications

用于非易失性低功耗自旋轨道电子学应用的磁性斯格明子

• 批准号: 1611570
• 负责人: Kang Wang
• 金额: $ 37.5万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-15 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1611570&HistoricalAwards=false
• 关键词: Magnetic; Skyrmion; Nonvolatile; Low; Power

This proposal aims to resolve the challenging issues related to the scaling of complementary metal-oxide-semiconductor (CMOS): power dissipation and variability. To achieve this goal, the proposed research explores the possibilities to build magnetic memory devices based on magnetic skyrmions for room-temperature applications featuring in nonvolatile, high density and low-power consumption. A magnetic skyrmion is a particle-like, topologically protected magnetic domain. As a nonvolatile information carrier, each individual skyrmion in a memory device can enable high-density, low-power operations due to the small size, the low driving current density and the extra topological protection. The proposed research will establish a framework for magnetic memory devices using topologically protected spin texture as the information carrier. The impact will be transformative and thus enables the construction of novel magnetic memory. The high-density memory will help accelerate the progress of the big data and internet-of-things era. Meanwhile, when integrated with the CMOS semiconductor technology, it potentially resolves the energy dissipation challenge and thus further advances the technology node. Additionally, this interdisciplinary research also has a vast educational impact, as the new knowledge from the spin orbit coupling engineering will have emerging educational meaning for new students. Students with education level from high school to undergraduate/graduate students, and postdocs (including women and minorities) will be exposed and trained in this inter- and multi-disciplinary and emerging fields of physical science and engineering as well as computer science through PI's participation of the high school and freshman outreach programs at UCLA. The training of students in these emerging disciplines will provide diverse human capital, versed in scientific method and experienced in the applications. The educational impact is further amplified by current outreach programs through the California NanoSystems and the NSF-ERC on Translational Applications of Nanoscale Multiferroic Systems.Although skyrmions can intrinsically exist in a group of so-called helimagnetic materials (B-20) compounds, skyrmions in magnetic multilayers or interfaces will be more compatible with existing magnetic recording/memory technologies. Thus, the proposed project focuses on the study of skyrmion creation, manipulation and detection in ferromagnetic layer/heavy-material (FM/HM) thin-film systems. This system provides the possibility to furthest adjust and tune the skyrmion properties for application purposes. The creation and annihilation of single, individual skyrmions will be experimentally realized and theoretically analyzed dynamically and statically. The manipulation of skyrmions can be controlled by currents via spin-orbit torque coming from the relativistic spin-orbit coupling (SOC). Each individual skyrmion can be detected using magnetoresistance effect via magnetic tunnel junctions. Single spin textures of single Skyrmions will be modeled via micromagnetic simulation. Knowledge and experience learnt from this study will enable electrically encoding and decoding of information; the use of commonly accessible thin film material systems with low-temperature process in this research automatically ensures devices to be fully compatible with current CMOS or magnetic recording technology. The proposed research is transformative since it invokes many unique innovations from (1) interfacial Dzyaloshinskii-Moriya interaction in FM/HM heterostructures to create skyrmion with controllable sizes; (2) effectively manipulation of skyrmion motion by the current-induced spin-orbit torque at the FM/HM interface; (3) the use of high-quality MTJ for information encoding and detection; (4) nanostructure engineering and voltage-controlled magnetic anisotropy (VCMA).

该提案旨在解决与互补金属氧化物半导体 (CMOS) 缩放相关的挑战性问题：功耗和可变性。为了实现这一目标，该研究探索了构建基于磁性斯格明子的磁性存储器件的可能性，用于室温应用，具有非易失性、高密度和低功耗的特点。磁性斯格明子是一种类似粒子、受拓扑保护的磁畴。作为非易失性信息载体，存储器件中的每个单独的斯格明子由于尺寸小、驱动电流密度低和额外的拓扑保护，可以实现高密度、低功耗操作。拟议的研究将建立一个使用拓扑保护的自旋纹理作为信息载体的磁存储器件框架。这种影响将是革命性的，从而使新型磁存储器的构建成为可能。高密度存储器将有助于加速大数据和物联网时代的进步。同时，当与CMOS半导体技术集成时，它有可能解决能量耗散的挑战，从而进一步推进技术节点。此外，这项跨学科研究还具有巨大的教育影响，因为自旋轨道耦合工程的新知识将对新生产生新的教育意义。通过PI的参与，从高中到本科生/研究生以及博士后（包括女性和少数族裔）教育水平的学生将在物理科学与工程以及计算机科学这一跨学科和新兴领域中得到接触和培训加州大学洛杉矶分校的高中和新生外展计划。这些新兴学科的学生培训将提供多样化的人力资本，精通科学方法并拥有丰富的应用经验。目前通过加州纳米系统和 NSF-ERC 关于纳米级多铁系统转化应用的推广计划进一步放大了教育影响。虽然斯格明子本质上可以存在于一组所谓的旋磁材料 (B-20) 化合物中，但斯格明子磁性多层或界面将与现有的磁记录/存储技术更加兼容。因此，拟议的项目重点研究铁磁层/重材料（FM/HM）薄膜系统中斯格明子的产生、操纵和检测。该系统提供了出于应用目的最大限度地调整和调节斯格明子特性的可能性。单个斯格明子的产生和湮灭将通过实验实现，并进行动态和静态的理论分析。斯格明子的操纵可以通过来自相对论自旋轨道耦合（SOC）的自旋轨道扭矩通过电流来控制。每个单独的斯格明子都可以通过磁隧道结利用磁阻效应进行检测。单个斯格明子的单自旋纹理将通过微磁模拟进行建模。 从这项研究中学到的知识和经验将使信息的电编码和解码成为可能；在这项研究中使用常见的薄膜材料系统和低温工艺自动确保设备与当前的 CMOS 或磁记录技术完全兼容。所提出的研究具有变革性，因为它引用了许多独特的创新：(1) FM/HM 异质结构中的界面 Dzyaloshinskii-Moriya 相互作用，以产生尺寸可控的斯格明子； (2)通过FM/HM界面处电流感应的自旋轨道扭矩有效操纵斯格明子运动； （3）采用高质量的MTJ进行信息编码和检测； (4)纳米结构工程和压控磁各向异性(VCMA)。