Direct observation of collective modes coupled to molecular orbital-driven charge transfer
Direct observation of collective modes coupled to molecular orbital-driven charge transfer
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DOI：
10.1126/science.aab3480
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发表时间：
2015-12-18
期刊：
影响因子：
56.9
通讯作者：
Miller, R. J. Dwayne
中科院分区：
文献类型：
--
作者：
Ishikawa, Tadahiko;Hayes, Stuart A.;Miller, R. J. Dwayne
关联电子系统可以经历超快光致相变，涉及电子和晶格结构的协同转变。理解这些现象需要识别耦合到电子状态的关键结构模式。我们报道了分子晶体Me4P[Pt（dmit）（2）]（2）的超快光响应，其表现出类似于热可及态之间的光致电荷转移，并演示了如何应用飞秒电子衍射直接观察相关的分子运动。即使对于这样一个复杂的系统，关键的大振幅模式可以通过眼睛识别，并涉及二聚体膨胀和Librational模式。动力学与时间分辨光学研究一致，揭示了电子，分子和晶格结构如何共同促进状态的超快切换。
Correlated electron systems can undergo ultrafast photoinduced phase transitions involving concerted transformations of electronic and lattice structure. Understanding these phenomena requires identifying the key structural modes that couple to the electronic states. We report the ultrafast photoresponse of the molecular crystal Me4P[Pt(dmit)(2)](2), which exhibits a photoinduced charge transfer similar to transitions between thermally accessible states, and demonstrate how femtosecond electron diffraction can be applied to directly observe the associated molecular motions. Even for such a complex system, the key large-amplitude modes can be identified by eye and involve a dimer expansion and a librational mode. The dynamics are consistent with the time-resolved optical study, revealing how the electronic, molecular, and lattice structures together facilitate ultrafast switching of the state.