Interaction of Coherent Electronic Spin Current with Antiferromagnetic Order

相干电子自旋流与反铁磁序的相互作用

• 批准号: 2003914
• 负责人: Satoru Emori
• 金额: $ 45万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2003914&HistoricalAwards=false
• 关键词: Interaction; Coherent; Electronic; Spin; Current

Non-technical AbstractAn electron carries a small angular momentum called spin. A flow of many electron spins, or spin current, may be an efficient way to transport information with minimal resistive heating or to flip stored information in magnetic recording media. To design practical spin-based information-technology devices, it is important to understand (1) how long a spin current travels before decaying and (2) how a spin current interacts with magnetic moments in recording media. This project answers these two questions for a specific advantageous type of magnetic materials, antiferromagnets, where magnetic moments are aligned anti-parallel (alternating) at the atomic length scale. Antiferromagnets operated by spin current potentially enable faster and more stable magnetic recording devices than conventional magnetic materials (ferromagnets, with parallel-aligned magnetic moments), but the basic physics of spin current in antiferromagnets is not well understood. This project fills this gap in knowledge through complementary experiments that determine spin-current decay lengths in tailored antiferromagnets, as well as through a powerful X-ray experiment that reveals the interaction of spin current with different magnetic atoms. Technical AbstractA spin current is said to be coherent when the spin polarization of its carriers (e.g., electrons) is locked in a uniform orientation or precessional phase. How a spin current loses its coherence, particularly as it interacts with magnetic order, is a crucial fundamental question in spintronics and quantum information science. The goal of this experimental project is to understand decoherence mechanisms of spin current carried by electrons that interact with alternating magnetic moments, i.e., antiferromagnetic order. This project fills a gap in basic understanding of spin decoherence in antiferromagnetic metals, which have recently gained considerable attention as platforms for next-generation spintronic devices. The specific objectives are: (1) to determine how the coherence length of transverse-polarized spin current is impacted by structural disorder and electronic scattering in antiferromagnetic metals, and (2) to determine how an electronic spin current transfers spin angular momentum to chemically distinct antiferromagnetic sublattices in ferrimagnetic alloys. These objectives are met by leveraging a unique combination of model systems (e.g., epitaxial thin films, nanostructured spin valves) and complementary characterization of film structure, magnetic order, microwave spin pumping, and magnetotransport. Furthermore, a pump-probe X-ray synchrotron method is utilized to gain an unprecedented time- and element-resolved insight into spin-current physics in multilayered antiferromagnetic systems. The distinct approach in this project to elucidate spin decoherence will have transformative impact on the growing discipline of antiferromagnetic spintronics.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.

非技术抽象电子具有一种称为自旋的小角动量。许多电子旋转或旋转电流的流动可能是一种有效的方法，可以使用最小的电阻加热或在磁性记录介质中翻转存储的信息。为了设计基于自旋的信息信息技术设备，重要的是要了解（1）旋转电流在衰减前传播多长时间，以及（2）旋转电流如何与录制介质中的磁矩相互作用。该项目回答了这两个问题，用于特定有利类型的磁性材料，抗铁磁铁，其中磁矩在原子长度尺度上对齐反平行（交替）。与传统的磁性材料（具有平行对齐的磁性矩）相比，由旋转电流操作的抗铁磁铁可能更快，更稳定的磁记录设备能够更快，更稳定。该项目通过互补的实验来填补这一差距，这些实验确定了量身定制的抗铁磁体中的自旋衰减长度，以及通过强大的X射线实验，该实验揭示了自旋电流与不同磁原子的相互作用。当其载体的自旋极化（例如电子）锁定在均匀的方向或进化阶段时，技术摘要自旋电流被认为是连贯的。旋转电流如何失去其连贯性，尤其是当它与磁性相互作用时，是旋转和量子信息科学中关键的基本问题。该实验项目的目的是了解与交替磁矩相互作用的电子携带的自旋电流的破坏机制，即抗磁磁序。该项目填补了对抗铁磁金属中旋转分解的基本理解的空白，这些金属最近作为下一代旋转器设备的平台引起了极大的关注。特定目标是：（1）确定抗磁性金属中结构障碍和电子散射的横向旋转旋转电流的相干长度如何，以及（2）确定电子旋转电流如何将旋转角动量转移到化学上不同的抗铁磁性抗铁磁性sublattices中。这些目标是通过利用模型系统（例如外延薄膜，纳米结构的自旋阀）和膜结构，磁性，微波旋转泵送和磁转运的互补表征的独特组合来实现的。此外，一种泵探针X射线同步器方法可用于获得对多层抗磁力磁性系统中自旋 - 电流物理学的前所未有的时间和元素分辨的洞察力。该项目阐明旋转反矫正的独特方法将对不断增长的反铁磁性旋转学学科产生变革性的影响。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力优点和更广泛影响的审查标准通过评估来获得支持的。

项目成果

Charge-spin interconversion in epitaxial Pt probed by spin-orbit torques in a magnetic insulator

• DOI: 10.1103/physrevmaterials.5.064404
• 发表时间: 2021-06-04
• 期刊: PHYSICAL REVIEW MATERIALS
• 影响因子: 3.4
• 作者: Li, Peng;Riddiford, Lauren J.;Emori, Satoru
• 通讯作者: Emori, Satoru

Room-temperature intrinsic and extrinsic damping in polycrystalline Fe thin films

• DOI: 10.1103/physrevb.105.174408
• 发表时间: 2021-09
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Shuang Wu;David A. Smith;P. Nakarmi;Anish Rai;M. Clavel;M. Hudait;Jing Zhao;F. Michel;C. Mewes;T. Mewes;S. Emori

Dephasing of transverse spin current in ferrimagnetic alloys

• DOI: 10.1103/physrevb.103.024443
• 发表时间: 2021-01-26
• 期刊: PHYSICAL REVIEW B
• 影响因子: 3.7
• 作者: Lim, Youngmin;Khodadadi, Behrouz;Emori, Satoru
• 通讯作者: Emori, Satoru

Ferrimagnetic insulators for spintronics: Beyond garnets

• DOI: 10.1063/5.0033259
• 发表时间: 2021-01-14
• 期刊: JOURNAL OF APPLIED PHYSICS
• 影响因子: 3.2
• 作者: Emori, Satoru;Li, Peng
• 通讯作者: Li, Peng

Experimental realization of linearly polarized x-ray detected ferromagnetic resonance

线偏振X射线检测铁磁共振的实验实现

• DOI: 10.1088/1367-2630/ac465f
• 发表时间: 2022
• 期刊: New Journal of Physics
• 影响因子: 3.3
• 作者: Klewe, C.;Emori, S.;Li, Q.;Yang, M.;Gray, B. A.;Jeon, H-M;Howe, B. M.;Suzuki, Y.;Qiu, Z. Q.;Shafer, P.
• 通讯作者: Shafer, P.