华东师范大学学报（自然科学版）Issue(2)：109-114,6.DOI:10.3969/j.issn.1000-5641.2018.02.011
飞秒激光激发磁性薄膜产生相干声学声子的研究
Coherent acoustic phonon inmagnetic thin films excited by femtosecond laser
颜佳琪 1李巍 1楼柿涛 1张晓磊1
作者信息
- 1. 华东师范大学精密光谱科学与技术国家重点实验室,上海200062
- 折叠
摘要
Abstract
The interaction between the femtosecond laser pulse and the MnIr layer in the magnetic thin film excites the coherent acoustic phonon with an initial phase of 90° and a propagation velocity of 4 300 m/s.The vibration frequency of the acoustic phonon is independent of the laser energy density and is inversely proportional to the total thickness of the magnetic thin film.And the acoustic phono can propagate in the adjacent metal layers due to the high lattice matching.The electron temperature in the magnetic thin film increases sharply absorbing by femtosecond laser pulse,then an decreasing electron temperature gradient with increasing depth is generated instantaneously by the absorption of the laser which lead to the lattice oscillate coherently in the depth direction,that is,the acoustic phonon.In addition,the frequency of the acoustic phonon changes caused by the applied magnetic field is within the experimental error range,indicating that the magnetic interaction is very weak compared to the electrical interaction in the lattice.关键词
飞秒激光/相干声学声子/泵浦-探测/磁性薄膜Key words
femtosecond laser/coherent acoustic phonon/pump-probe/magnetic film分类
数理科学引用本文复制引用
颜佳琪,李巍,楼柿涛,张晓磊..飞秒激光激发磁性薄膜产生相干声学声子的研究[J].华东师范大学学报（自然科学版）,2018,(2):109-114,6.
