Time-resolved X-ray diffraction from coherent phonons during a laser-induced phase transition
Time-resolved X-ray diffraction from coherent phonons during a laser-induced phase transition
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DOI：
10.1103/physrevlett.84.111
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发表时间：
2000-01-03
影响因子：
8.6
通讯作者：
Falcone, RW
中科院分区：
文献类型：
--
作者：
Lindenberg, AM;Kang, I;Falcone, RW
本文利用时间分辨X射线衍射技术研究了激光激发InSb晶体中脉冲相干声子的散射。所观察到的频率和阻尼率是在协议的基础上耦合到激光诱导应变分布的解析解的动态衍射理论的模型。结果是一致的12 ps的热电子-声学声子耦合时间连同从变形势相互作用的瞬时分量。在临界激光能量密度以上，我们证明了向无序态过渡的第一步是激发大振幅的相干原子运动。
Time-resolved x-ray diffraction with picosecond temporal resolution is used to observe scattering from impulsively generated coherent acoustic phonons in laser-excited InSb crystals. The observed frequencies and damping rates are in agreement with a model based on dynamical diffraction theory coupled to analytic solutions for the laser-induced strain profile. The results are consistent with a 12 ps thermal electron-acoustic phonon coupling time together with an instantaneous component from the deformation-potential interaction. Above a critical laser fluence, we show that the first step in the transition to a disordered state is the excitation of large amplitude, coherent atomic motion.