MRI: Development of a system for low temperature optical measurement of 3D magnon, plasmon and spin torque transfer dynamics.

MRI：开发用于 3D 磁振子、等离激元和自旋扭矩传递动力学低温光学测量的系统。

• 批准号: 1624976
• 负责人: Matthew Doty
• 金额: $ 65.07万
• 依托单位: University of Delaware
• 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: 2016-09-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1624976&HistoricalAwards=false
• 关键词: MRI; Development; system; low; temperature

Over the past 15 years scientists and engineers have realized that integrating logic and information storage functions could dramatically improve the energy efficiency of computing devices and enable new and more powerful computing paradigms. Promising materials for creating such a device include those materials in which electrical current strongly interacts with the spin of electrons. The spin of an electron can be thought of as a tiny bar magnet attached to the electron in which the north pole of the magnet can be oriented up, down, or in any other direction. To develop new computing platforms that integrate charge and spin functionality, it is necessary to study how these spins change direction in response to external stimuli such as electrical current or pulses of light. These changes occur very quickly in about one billionth of one second. This award supports the development of an instrument to study spin reorientation by measuring the spin direction with extremely short pulses of light that arrive at the sample at precisely controlled times relative to external stimuli such as an electrical current or a beam of light. Measurements will be carried out at very low temperatures to isolate and understand the fundamental physical processes. This knowledge will provide the scientific foundation for engineering appropriate materials for application in future computing devices. The work is being coordinated with a new graduate-level course on the materials under investigation and support the training of one postdoctoral researcher and two undergraduate researchers.Spin-based phenomena in topological insulators and magnetic heterostructures have attracted a great deal of attention from the perspective of both fundamental science and device development. However, the underlying physical origin of many of these phenomena remains vague. Moreover, the dynamics of these phenomena, which are critical for device applications, remain poorly understood. This award supports the development of an instrument that will enable ultrafast optical measurements of collective magnetic and charge excitations and spin transfer dynamics at low temperatures and in three-dimensional magnetic fields. The new instrument will allow scientists to answer fundamental scientific questions about quantum materials, magnetic heterostructures, and other "quantum engineered" heterogeneous materials and identify routes to tailor these heterogeneous materials for spintronic, optoelectronic, and quantum device applications. The new instrument will enable the first ultrafast measurements of the dynamics of spin transfer torque. The three dimensional resolution and integrated optical, magnetic, and electrical control will allow scientists to separate, understand, and ultimately control competing processes. The instrument will also provide unprecedented measurement of magnon and plasmon dynamics in topological insulators and heterogeneous materials designed to control the emergence of interfacial phenomena with unique quantum mechanical properties. Successful development of the instrument will enable new interactions between fundamental science, applied science, and device engineering fields. It will enable the breakthroughs required for widespread adoption of "exotic" materials in device technologies. Conceptual aspects of the research enabled by this instrument will be integrated into new graduate and undergraduate courses and science education outreach programs. Members of underrepresented groups will be actively recruited for both the postdoctoral and undergraduate researcher positions supported by the award.

在过去的15年里，科学家和工程师已经意识到，集成逻辑和信息存储功能可以大大提高计算设备的能源效率，并实现新的、更强大的计算模式。用于制造这种装置的有希望的材料包括电流与电子自旋强烈相互作用的那些材料。电子的自旋可以被认为是附着在电子上的一个微小的条形磁铁，磁铁的北极可以向上、向下或任何其他方向。为了开发集成电荷和自旋功能的新计算平台，有必要研究这些自旋如何响应外部刺激（如电流或光脉冲）而改变方向。这些变化在十亿分之一秒内发生得非常快。该奖项支持开发一种仪器，通过使用极短的光脉冲测量自旋方向来研究自旋重定向，这些光脉冲相对于外部刺激（如电流或光束）在精确控制的时间到达样品。测量将在非常低的温度下进行，以分离和理解基本的物理过程。这些知识将为设计适用于未来计算设备的材料提供科学基础。这项工作正在与一个新的研究生课程相协调，该课程涉及正在研究的材料，并支持培养一名博士后研究人员和两名本科生研究人员。拓扑绝缘体和磁性异质结构中的自旋现象从基础科学和器件开发的角度都引起了极大的关注。然而，许多这些现象的基本物理起源仍然模糊不清。此外，这些现象的动力学，这是关键的设备应用程序，仍然知之甚少。该奖项支持开发一种仪器，该仪器将能够在低温和三维磁场中对集体磁和电荷激发以及自旋转移动力学进行超快光学测量。新仪器将使科学家能够回答有关量子材料，磁性异质结构和其他“量子工程”异质材料的基本科学问题，并确定为自旋电子，光电和量子器件应用定制这些异质材料的路线。新仪器将实现自旋转移扭矩动力学的首次超快测量。三维分辨率和集成的光学，磁性和电气控制将使科学家能够分离，理解并最终控制竞争过程。该仪器还将提供拓扑绝缘体和异质材料中磁振子和等离子体动力学的前所未有的测量，旨在控制具有独特量子力学特性的界面现象的出现。该仪器的成功开发将使基础科学，应用科学和设备工程领域之间的新的相互作用。它将实现在设备技术中广泛采用“奇异”材料所需的突破。该工具所支持的研究的概念方面将被纳入新的研究生和本科生课程以及科学教育推广计划。代表性不足的群体的成员将被积极招募的博士后和本科生研究员职位由该奖项支持。

项目成果

Investigation of spin orbit torque driven dynamics in ferromagnetic heterostructures

• DOI: 10.1016/j.jmmm.2019.166211
• 发表时间: 2019-10
• 期刊: Journal of Magnetism and Magnetic Materials
• 影响因子: 2.7
• 作者: Xinran Zhou;Hang Chen;Y. Ou;Tao Wang;Rasoul Barri;Harsha Kannan;J. Xiao;M. Doty

Vector-Resolved Magnetooptic Kerr Effect Measurements of Spin–Orbit Torque

自旋轨道扭矩的矢量分辨磁光克尔效应测量

• DOI: 10.1109/tmag.2018.2873129
• 发表时间: 2019
• 期刊: IEEE Transactions on Magnetics
• 影响因子: 2.1
• 作者: Celik, Halise;Kannan, Harsha;Wang, Tao;Mellnik, Alex R.;Fan, Xin;Zhou, Xinran;Barri, Rasoul;Ralph, Daniel C.;Doty, Matthew F.;Lorenz, Virginia O.
• 通讯作者: Lorenz, Virginia O.