Antiferromagnet-based Ultrafast Magnetic Memory Devices

基于反铁磁体的超快磁存储器件

• 批准号: 1808826
• 负责人: Luqiao Liu
• 金额: $ 36万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-06-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1808826&HistoricalAwards=false
• 关键词: Antiferromagnet; based; Ultrafast; Magnetic; Memory

Compared with existing computer memories, memories based on magnetic materials have advantages of lower power consumption and better scalability. Moreover, information is retained in magnetic memories in the absence of power supply, providing possibilities of new computing schemes. However, existing magnetic memory devices have relatively low operating speed, which greatly limits their application. In this proposal, magnetic memory devices with ultrafast writing speed (1 nanosecond) will be developed, which can potentially bring in revolutionary changes in memory and data storage industry. The realization of the ultrafast control of magnetic dynamics could also advance understanding on the properties of magnetic materials. In addition to these broad scientific impacts, this project also provides students with unique transdisciplinary training opportunities. This research project is proposed to be integrated with the educational missions, including inspiring career interest of K-12 students in science and engineering; providing undergraduate students with cutting-edge research opportunities; and preparing students for future careers through curriculum development and interdisciplinary collaboration.To realize ultrafast magnetic memories, this proposal tries to leverage the fast development of fabrication techniques on spintronic devices with the recent advancement in new magnetic materials. Particularly, antiferromagnet will be studied for realizing magnetic memories with superior speed and high storage density. Compared with regular ferromagnet, antiferromagnet has ultrafast dynamics due to the high magnetic resonance frequency. However so far the lack of efficient control and detection mechanisms in antiferromagnet has made it challenging for practical implementations of antiferromagnet in magnetic memory devices. In this proposal, the PI focuses on spintronic devices made from antiferromagnet with internally broken inversion symmetry, where the inequality of the two sub-lattices allows the generation of staggered spin orbit torque and provides the possibility for magnetic probing and manipulation. The goals of the proposed experimental efforts include quantitatively determining the writing efficiency as well as exploring and optimizing the reading mechanisms of antiferromagnet. Specifically, a unique scheme for measuring antiferromagnet spin orbit torque is proposed, through which the underlying mechanisms for antiferromagnet switching will be revealed and quantified. Moreover, the switching speed of antiferromagnet devices will also be evaluated and the limiting factors on efficient magnetic switching will be determined through the antiferromagnet domain movement experiment. Finally, a high ON/OFF ratio will be pursued through the study of tunneling anisotropy magnetoresistance, which can lead to an efficient reading mechanism for antiferromagnet devices. In overall, the proposed research activities will not only facilitate the realization of practical antiferromagnet magnetic memory devices with fast accessing time and high density, but also enhance understanding on the current induced dynamics in antiferromagnet and widen awareness of the spin charge interaction in antiferromagnetically coupled systems.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.

与现有的计算机存储器相比，基于磁性材料的存储器具有功耗低、可扩展性好等优点。此外，在没有电源的情况下，信息仍保留在磁存储器中，为新的计算方案提供了可能性。然而，现有的磁存储器件的运行速度相对较低，这大大限制了它们的应用。通过该提案，将开发具有超快写入速度（1纳秒）的磁存储器件，这可能会给存储器和数据存储行业带来革命性的变化。磁动力学的超快控制的实现也可以促进对磁性材料性质的认识。除了这些广泛的科学影响外，该项目还为学生提供了独特的跨学科培训机会。本研究项目拟与教育使命相结合，包括激发K-12学生对理工科的职业兴趣；为本科生提供前沿研究机会；并通过课程开发和跨学科合作为学生未来的职业生涯做好准备。为了实现超快磁记忆，本方案试图利用自旋电子器件制造技术的快速发展和新磁性材料的最新进展。特别地，反铁磁体将被研究用于实现高速度和高存储密度的磁存储器。与常规铁磁体相比，反铁磁体由于共振频率高，具有超快的动力学特性。然而，到目前为止，反铁磁体缺乏有效的控制和检测机制，这给反铁磁体在磁存储器件中的实际实现带来了挑战。在这个提议中，PI专注于由内部逆对称性破缺的反铁磁体制成的自旋电子器件，其中两个子晶格的不平等允许产生交错的自旋轨道扭矩，并为磁探测和操纵提供了可能性。本实验的目标包括定量确定反铁磁体的写入效率以及探索和优化反铁磁体的读取机制。具体而言，提出了一种独特的测量反铁磁体自旋轨道转矩的方案，通过该方案可以揭示和量化反铁磁体开关的潜在机制。此外，还将通过反铁磁畴运动实验来评估反铁磁器件的开关速度，并确定有效磁开关的限制因素。最后，将通过研究隧道各向异性磁电阻来追求高开/关比，这可以导致反铁磁体器件的高效读取机制。总的来说，本文的研究活动不仅有助于实现具有快速访问时间和高密度的实用反铁磁体磁存储器件，而且有助于加深对反铁磁体中电流诱导动力学的理解，并扩大对反铁磁体耦合系统中自旋电荷相互作用的认识。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Spin-Orbit-Torque Switching Mediated by an Antiferromagnetic Insulator

• DOI: 10.1103/physrevapplied.11.044070
• 发表时间: 2019-04
• 期刊: Physical Review Applied
• 影响因子: 4.6
• 作者: Hailong Wang;Joseph Finley;Pengxiang Zhang;Jiahao Han;J. Hou;Luqiao Liu

Gigahertz Frequency Antiferromagnetic Resonance and Strong Magnon-Magnon Coupling in the Layered Crystal CrCl3

• DOI: 10.1103/physrevlett.123.047204
• 发表时间: 2019-07-24
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: MacNeill, David;Hou, Justin T.;Liu, Luqiao
• 通讯作者: Liu, Luqiao

Resonant Spin Transmission Mediated by Magnons in a Magnetic Insulator Multilayer Structure

• DOI: 10.1002/adma.202008555
• 发表时间: 2021-04-25
• 期刊: ADVANCED MATERIALS
• 影响因子: 29.4
• 作者: Fan, Yabin;Finley, Joseph;Liu, Luqiao
• 通讯作者: Liu, Luqiao

Manipulation of Coupling and Magnon Transport in Magnetic Metal-Insulator Hybrid Structures

• DOI: 10.1103/physrevapplied.13.061002
• 发表时间: 2020-06-15
• 期刊: PHYSICAL REVIEW APPLIED
• 影响因子: 4.6
• 作者: Fan, Yabin;Quarterman, P.;Liu, Luqiao
• 通讯作者: Liu, Luqiao

Birefringence-like spin transport via linearly polarized antiferromagnetic magnons

• DOI: 10.1038/s41565-020-0703-8
• 发表时间: 2020-06-01
• 期刊: NATURE NANOTECHNOLOGY
• 影响因子: 38.3
• 作者: Han, Jiahao;Zhang, Pengxiang;Liu, Luqiao
• 通讯作者: Liu, Luqiao