Ultrafast lattice dynamics studied by femtosecond time-resolved electron diffraction

我们构建了超快电子衍射系统。利用光电阴极电子枪在透射和反射几何上获得了HOPG和云母的电子衍射图像。在传输几何结构中，我们成功地获得了薄金单晶的Bragg光斑在10ps内衰减的时间分辨信号。我们还测量了在2ps内显示Bragg光斑强度衰减的IrTe2，表明电子-声子耦合比金的更强。同时，估计该系统的总时间分辨率优于2ps。对铁基超导体的研究正在进行中。

We constructed the ultrafast electron diffraction system. We obtained the electron diffraction images of HOPG or mica by using photocathode electron gun in the transmission and reflection geometries. In the transmission geometry, we successfully obtained the time-resolved signal from the Bragg spots of thin Au single crystals, which decreases within 10 ps. We also measured the IrTe2 which shows the decay of the Bragg spot intensity within 2ps, indicative of the electron-phonon coupling stronger than that of gold. At the same time, total time resolution of this system was estimated to be better than 2ps. Investigation on the iron-based superconductors are now in progress.