基于超快自旋电子学太赫兹发射源的研究与应用

Research and Application of Spintronic Terahertz Emitter Based on Ultrafast Spintronics

太赫兹科学技术在生物传感、显微成像、无线通信、无损检测等领域展现出了巨大的研究潜力和应用价值.然而,目前制约太赫兹技术快速发展的瓶颈之一在于缺乏高效率、高集成度、低功耗以及易调制的太赫兹发射源器件.自旋太赫兹源基于铁磁层/非磁层异质结体系中的超快自旋-电荷转换产生太赫兹辐射,具有宽频带、低成本、易加工、高场强等优势,近年来吸引了许多国内外学者的研究兴趣.本文首先对基于超快自旋动力学的太赫兹发射机理进行了简要介绍,分析并综述了其效率调控与优化的可行方案;并进一步针对自旋太赫兹的新型发射机理及研究应用前景进行了重点分析,新型发射包括基于不同手性及偏振态自旋太赫兹的发射及基于新材料体系的自旋太赫兹发射源探索,应用前景包括自旋太赫兹光谱技术、自旋太赫兹成像技术及自旋太赫兹发射-调控一体化技术等;最后总结全文,并对未来基于超快自旋电子学太赫兹发射源的改善、探索及应用,以及基于太赫兹电磁脉冲研究自旋电子学的微观机理做出了展望.

Terahertz(THz) technology has shown great research potential and application value in biosensing, microscopic imaging, wireless communication, nondestructive testing and other fields. However, one of the bottlenecks restricting the rapid development of THz technology is the lack of high efficiency, high integration, low power consumption and easily modulated THz emitters. The THz radiation generated by spintronic terahertz emitter(STE) based on the ultrafast spin to charge conversion in ferromagnetic/non-magnetic heterostructure has the advantages of wide frequency band, low cost, easy fabrication and high field intensity, which has attracted the interest of many scholars at home and abroad in recent years. In this paper, the THz emission mechanism based on ultrafast spin dynamics are briefly introduced. And the feasible schemes to regulate and optimize its efficiency are further analyzed and reviewed. Furthermore, the new emission mechanisms and application prospects of STE are analyzed. New emission mechanisms include the emission of spintronic THz with different chirality and polarization states, and the exploration of STE based on new-type materials. And application prospects include spintronic THz spectroscopy, spintronic THz imaging and spintronic THz emission-regulation integration technology. Finally, the paper is summarized, and the future improvement, exploration and application of ultrafast spintronic terahertz emission sources, as well as the microscopic mechanism of spintronics driven by terahertz electromagnetic pulse are prospected.