Okino Tomoya, Furukawa Yusuke, Nabekawa Yasuo, Miyabe Shungo, Amani Eilanlou A, Takahashi Eiji J, Yamanouchi Kaoru, Midorikawa Katsumi
Attosecond Science Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Sci Adv. 2015 Sep 25;1(8):e1500356. doi: 10.1126/sciadv.1500356. eCollection 2015 Sep.
Capturing electron motion in a molecule is the basis of understanding or steering chemical reactions. Nonlinear Fourier transform spectroscopy using an attosecond-pump/attosecond-probe technique is used to observe an attosecond electron wave packet in a nitrogen molecule in real time. The 500-as electronic motion between two bound electronic states in a nitrogen molecule is captured by measuring the fragment ions with the same kinetic energy generated in sequential two-photon dissociative ionization processes. The temporal evolution of electronic coherence originating from various electronic states is visualized via the fragment ions appearing after irradiation of the probe pulse. This observation of an attosecond molecular electron wave packet is a critical step in understanding coupled nuclear and electron motion in polyatomic and biological molecules to explore attochemistry.
捕捉分子中的电子运动是理解或控制化学反应的基础。利用阿秒脉冲泵浦/阿秒脉冲探测技术的非线性傅里叶变换光谱法被用于实时观测氮分子中的阿秒电子波包。通过测量在连续双光子解离电离过程中产生的具有相同动能的碎片离子，捕捉到了氮分子中两个束缚电子态之间500阿秒的电子运动。通过探测脉冲照射后出现的碎片离子，可视化了源自各种电子态的电子相干的时间演化。这种对阿秒分子电子波包的观测是理解多原子和生物分子中核与电子耦合运动以探索阿秒化学的关键一步。
