Attosecond correlation dynamics
Attosecond correlation dynamics
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DOI：
10.1038/nphys3941
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发表时间：
2017-03-01
期刊：
影响因子：
19.6
通讯作者：
Schultze, M.
中科院分区：
文献类型：
--
作者：
Ossiander, M.;Siegrist, F.;Schultze, M.
电子的光电发射通常被视为单粒子现象。与阿秒条纹光谱，我们观察到这个单一的活性电子近似记录高达6阿秒延迟的逐出光电子由于电子相关性的故障。我们记录了依赖于光子能量的电子发射时间，由极紫外光子从氦基态释放，要么使离子处于基态，要么将其激发成震荡态。我们确定了一个光场驱动的直流斯塔克位移后形成的纠缠光电发射作为一个关键的贡献，所观察到的相关时间漂移的电荷不对称的离子态。这些发现使一个完整的波包重建，是普遍的所有极化的初始和最终状态。亚阿秒协议与量子力学从头算模型使我们能够确定绝对零的时间在光电效应的精度优于1/25的原子单位的时间。
Photoemission of an electron is commonly treated as a one-particle phenomenon. With attosecond streaking spectroscopy we observe the breakdown of this single active-electron approximation by recording up to six attoseconds retardation of the dislodged photoelectron due to electronic correlations. We recorded the photon-energy-dependent emission timing of electrons, released from the helium ground state by an extreme-ultraviolet photon, either leaving the ion in its ground state or exciting it into a shake-up state. We identify an optical field-driven d.c. Stark shift of charge-asymmetric ionic states formed after the entangled photoemission as a key contribution to the observed correlation time shift. These findings enable a complete wavepacket reconstruction and are universal for all polarized initial and final states. Sub-attosecond agreement with quantum mechanical ab initio modelling allows us to determine the absolute zero of time in the photoelectric effect to a precision better than 1/25th of the atomic unit of time.