Unveiling of Terahertz Emission from Ultrafast Demagnetization and the Anomalous Hall Effect in a Single Ferromagnetic Film  

作　　者：蓝志强 李章顺 徐浩然 刘凡 金钻明 彭滟 朱亦鸣 Zhiqiang Lan;Zhangshun Li;Haoran Xu;Fan Liu;Zuanming Jin;Yan Peng;Yiming Zhu(Terahertz Technology Innovation Research Institute,Terahertz Spectrum and Imaging Technology Cooperative Innovation Center,Shanghai Key Lab of Modern Optical System,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]Terahertz Technology Innovation Research Institute,Terahertz Spectrum and Imaging Technology Cooperative Innovation Center,Shanghai Key Lab of Modern Optical System,University of Shanghai for Science and Technology,Shanghai 200093,China

出　　处：《Chinese Physics Letters》2024年第4期45-50,共6页中国物理快报（英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant Nos.2023YFF0719200 and 2022YFA1404004);the National Natural Science Foundation of China(Grant Nos.61988102,62322115,61975110,and 62335012);the 111 Project(Grant No.D18014);the Key Project supported by Science and Technology Commission Shanghai Municipality(Grant No.YDZX20193100004960);Science and Technology Commission of Shanghai Municipality(Grant No.22JC1400200);General Administration of Customs People’s Republic of China(Grant No.2019HK006)。

摘　　要：Using THz emission spectroscopy,we investigate the elementary spin dynamics in ferromagnetic single-layer Fe on a sub-picosecond timescale.We demonstrate that THz radiation changes its polarity with reversal of the magnetization applied by the external magnetic field.In addition,it is found that the sign of THz polarity excited from different sides is defined by the thickness of the Fe layer and Fe/dielectric interface.Based on the thickness and symmetry dependences of THz emission,we experimentally distinguish between the two major contributions:ultrafast demagnetization and the anomalous Hall effect.Our experimental results not only enrich understanding of THz electromagnetic generation induced by femtosecond laser pulses but also provide a practical way to access laser-induced ultrafast spin dynamics in magnetic structures.

关 键 词：MAGNETIC MAGNETIZATION polarity 

分 类 号：O469[理学—凝聚态物理]