论文标题
超快光诱导的剪切应变由时间分辨X射线衍射探测：模型多效性Bifeo $ _3 $作为案例研究
Ultrafast light-induced shear strain probed by time-resolved X-ray diffraction: the model multiferroic BiFeO$_3$ as a case study
论文作者
论文摘要
在超短时间尺度上启用复杂系统的光控制会产生丰富的物理，并具有有希望的应用。尽管至关重要，但纵向和剪切照片引起的菌株的定量确定仍然具有挑战性。在这里，通过仔细检查不对称的bragg峰对$（\ pm H01）$，使用picsecond time Classondercolved x射线衍射实验$ _3 $，我们同时确定纵向和剪切菌株。这些菌株的相对幅度只有在热过程和非热过程都有助于声音声子光学生成过程时才可以解释这些菌株。重要的是，我们还揭示了纵向应变相对于剪切的动态响应的差异，这是由于我们模型良好复制的准钟形和准透明声模式的相互作用。
Enabling the light-control of complex systems on ultra-short timescales gives rise to rich physics with promising applications. While crucial, the quantitative determination of both the longitudinal and shear photo-induced strains still remains challenging. Here, by scrutinizing asymmetric Bragg peaks pairs $(\pm h01)$ using picosecond time-resolved X-ray diffraction experiments in BiFeO$_3$, we simultaneously determine the longitudinal and shear strains. The relative amplitude of those strains can be explained only if both thermal and non-thermal processes contribute to the acoustic phonon photogeneration process. Importantly, we also reveal a difference of the dynamical response of the longitudinal strain with respect to the shear one due to an interplay of quasi-longitudinal and quasi-transverse acoustic modes, well reproduced by our model.
