超快自旋电子学研究进展  

Progress in ultrafast spintronics research

作　　者：芦闻天 袁喆 LU Wen-Tian;YUAN Zhe(Center for Advanced Quantum Studies,Department of Physics,Beijing Normal University,Beijing 100875,China)

机构地区：[1]北京师范大学物理学系高等量子研究中心,北京100875

出　　处：《中国科学：物理学、力学、天文学》2022年第7期94-119,共26页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:61774018,12174028)资助项目。

摘　　要：超快自旋电子学是当前信息处理技术革新最具前景的领域之一.与传统的电子学器件相比,基于自旋的新型信息器件具有功耗低、速度快、非易失性等特点.探究有关自旋的新颖物理现象和机制将极大地促进新一代磁性信息器件的开发与研制.本文综述在超快时间尺度磁学与自旋电子学研究的一系列进展.首先简要介绍自旋电子学的历史背景和飞秒激光诱导铁磁体超快退磁的发现;概括超快自旋动力学的相关物理机制与理论,包括唯象学三温度模型、含时密度泛函理论计算、Elliott-Yafet型自旋翻转机制等局域退磁机制和非局域超扩散自旋输运模型;深入总结亚铁磁和铁磁金属全光翻转的最新实验和理论研究;阐述超短激光诱导热电子自旋输运的发现和对超快磁动力学的影响,超快自旋转移矩效应,半导体材料超快自旋注入的实现及热电子输运中的自旋积累与耗散;分析自旋电子太赫兹源在性能优化与调控方面取得的进展;最后指出当前超快自旋电子学领域存在的挑战,并展望未来该领域的若干研究重点.Ultrafast spintronics is one of the most promising fields for information processing technology innovation.When compared with traditional electronic devices,new spin-based devices have advantages such as low power consumption,high speed,and nonvolatility.Exploring novel physical phenomena and mechanisms relating to electronic spins significantly promotes the development of next-generation spintronic devices.In this review,we outline a sequence of advances in the fields of ultrafast magnetics and spintronics.First,a quick overview of spintronics and the discovery of ultrafast demagnetization induced by a femtosecond laser is provided.The proposed physical mechanisms and theories of ultrafast spin dynamics are then summarized,including the phenomenological three-temperature model,computations based on the time-dependent density functional theory,the Elliott-Yafet spin-ffip mechanism,and the nonlocal superdiffusive spin transport model.Following that,the most recent experimental and theoretical studies on all-optical switching of ferrimagnetic and ferromagnetic metals are thoroughly reviewed.Furthermore,the discovery of hot-electron spin transport induced by ultrashort lasers as well as its inffuence on ultrafast magnetization dynamics,ultrafast spin transfer torque,spin injection into semiconductors,and spin accumulation and dissipation in hot-electron transport are described.The advancements in the optimization and manipulation of spintronics-based terahertz emitters are reviewed and analyzed.Finally,we discuss the current challenges in ultrafast spintronics research as well as possible future studies.

关 键 词：自旋电子学 超快退磁 自旋极化输运 全光翻转 磁性多层膜 太赫兹发射 

分 类 号：O469[理学—凝聚态物理]