Abstract
The hitherto unexplored two-photon doubly excited states [ were experimentally identified using the seeded, fully coherent, intense extreme ultraviolet free-electron laser FERMI. These states undergo ultrafast interatomic Coulombic decay (ICD), which predominantly produces singly ionized dimers. In order to obtain the rate of ICD, the resulting yield of ions was recorded as a function of delay between the extreme ultraviolet pump and UV probe laser pulses. The extracted lifetimes of the long-lived doubly excited states, , and of the short-lived ones, less than 150 fs, are in good agreement with ab initio quantum mechanical calculations.
- Received 5 August 2016
DOI:https://doi.org/10.1103/PhysRevLett.118.033202
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