Abstract
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.
基金项目
国家重点研发计划(2023YFF0719200)
国家重点研发计划(2022YFA1404004)
国家自然科学基金(61988102)
国家自然科学基金(62322115)
国家自然科学基金(61975110)
国家自然科学基金(62335012)
高等学校学科创新引智计划(111计划)(D18014)
Key Project supported by science and Technology Commission Shanghai Municipality(YDZX20193100004960)
上海市科委项目(22JC1400200)
General Administration of Customs People's Republic of China(2019HK006)
维普
万方数据