单层铁磁体中的超快太赫兹辐射研究进展

Research progress of ultrafast terahertz radiation in single-layer ferromagnets

摘要:

宽频带太赫兹辐射源在太赫兹科学与技术中有着迫切的实际应用需求，是构建波谱和成像为代表的太赫兹应用系统的核心器件。与常用的商用太赫兹源相比，自旋光电子学太赫兹辐射源具有超宽频谱、固态稳定以及成本低等一系列优点。目前，基于自旋光电子学太赫兹辐射源的理论、材料和器件技术研究尚处于起步阶段。本文主要总结了近年来单层铁磁层的太赫兹产生机理以及太赫兹辐射信号的极性与激发构型之间的关系。通过改变磁场方向、入射激光方向和样品入射方向可有效区分超快退磁、反常霍尔效应和反常能斯特效应对太赫兹辐射特性的贡献，为太赫兹自旋光电子学领域的研究提供参考。

Abstract:

Broadband terahertz radiation sources have an urgent practical application demand in terahertz science and technology, and are the core components for constructing terahertz application systems represented by spectroscopy and imaging. Compared with commonly used commercial terahertz sources, spin-optoelectronics-based terahertz radiation sources have a series of advantages such as ultra-wide frequency spectrum, solid-state stability, and low cost. Currently, the research on the theory, materials, and device technology of spin-optoelectronics-based terahertz radiation sources is still in its infancy. This paper mainly summarizes the terahertz generation mechanism of single-layer ferromagnetic layers in recent years, and the relationship between the polarity of terahertz radiation signals and the excitation configuration. By changing the direction of the magnetic field, the direction of the incident laser, and the direction of sample incidence, the contributions of ultrafast demagnetization, Anomalous Hall Effect(AHE), and Anomalous Nernst Effect(ANE) to the terahertz radiation characteristics can be effectively distinguished, providing a reference for the research in the field of terahertz spin-optoelectronics.