Charge transfer in transduction of light to electrical or chemical energy at heterojunctions of metals with semiconductors or semimetals is believed to occur by photogenerated hot electrons in metal undergoing incoherent internal photoemission through the heterojunction interface. Charge transfer, however, can also occur coherently by dipole coupling of electronic bands at the heterojunction interface. Microscopic physical insights into how transfer occurs can be elucidated by following the coherent polarization of the donor and acceptor states on the time scale of electronic dephasing. By time-resolved multiphoton photoemission spectroscopy (MPP), we investigate the coherent electron transfer from an interface state that forms upon chemisorption of Ag nanoclusters onto graphite to a $\sigma$ symmetry interlayer band of graphite. Multidimensional MPP spectroscopy reveals a resonant two-photon transition, which dephases within 10 fs completing the coherent transfer.

中文翻译：

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Ag /石墨异质结界面处的相干电子转移

据信，在金属与半导体或半金属的异质结处将光转换为电能或化学能时，电荷转移是通过金属中通过异质结界面进行非相干内部光发射的光生热电子发生的。但是，电荷转移也可以通过异质结界面处电子带的偶极耦合而相干地发生。可以通过在电子移相的时间尺度上遵循供体和受体状态的相干极化，来阐明关于如何发生转移的微观物理见解。通过时间分辨多光子光发射光谱法（MPP），我们研究了从银纳米团簇化学吸附到石墨上时形成的界面态的相干电子转移。$\sigma$石墨的对称夹层带。多维MPP光谱显示了共振的两个光子跃迁，该跃迁在10 fs内完成了相干转移。