Glownia J M, Natan A, Cryan J P, Hartsock R, Kozina M, Minitti M P, Nelson S, Robinson J, Sato T, van Driel T, Welch G, Weninger C, Zhu D, Bucksbaum P H
Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Phys Rev Lett. 2016 Oct 7;117(15):153003. doi: 10.1103/PhysRevLett.117.153003. Epub 2016 Oct 3.
Time-resolved femtosecond x-ray diffraction patterns from laser-excited molecular iodine are used to create a movie of intramolecular motion with a temporal and spatial resolution of 30 fs and 0.3 Å. This high fidelity is due to interference between the nonstationary excitation and the stationary initial charge distribution. The initial state is used as the local oscillator for heterodyne amplification of the excited charge distribution to retrieve real-space movies of atomic motion on ångstrom and femtosecond scales. This x-ray interference has not been employed to image internal motion in molecules before. Coherent vibrational motion and dispersion, dissociation, and rotational dephasing are all clearly visible in the data, thereby demonstrating the stunning sensitivity of heterodyne methods.
来自激光激发分子碘的时间分辨飞秒X射线衍射图案被用于创建一部分子内运动的影片，其时间和空间分辨率分别为30飞秒和0.3埃。这种高保真度源于非平稳激发与静止初始电荷分布之间的干涉。初始状态被用作外差放大激发电荷分布的本地振荡器，以获取埃和飞秒尺度上原子运动的实空间影片。此前尚未采用这种X射线干涉来对分子内部运动进行成像。在数据中，相干振动运动、色散、解离和旋转退相都清晰可见，从而证明了外差方法惊人的灵敏度。
