Multi-channel electronic and vibrational dynamics in polyatomic resonant high-order harmonic generation

作者：Ferre A; Boguslavskiy A E; Dagan M; Blanchet V; Bruner B D; Burgy F; Camper A; Descamps D; Fabre B; Fedorov N; Gaudin J; Geoffroy G; Mikosch J; Patchkovskii S; Petit S; Ruchon T; Soifer H; Staedter D; Wilkinson I; Stolow A; Dudovich N; Mairesse Y^*

来源：Nature Communications, 2015, 6(1): UNSP 5952.

DOI：10.1038/ncomms6952

High-order harmonic generation in polyatomic molecules generally involves multiple channels of ionization. Their relative contribution can be strongly influenced by the presence of resonances, whose assignment remains a major challenge for high-harmonic spectroscopy. Here we present a multi-modal approach for the investigation of unaligned polyatomic molecules, using SF6 as an example. We combine methods from extreme-ultraviolet spectroscopy, above-threshold ionization and attosecond metrology. Fragment-resolved above-threshold ionization measurements reveal that strong-field ionization opens at least three channels. A shape resonance in one of them is found to dominate the signal in the 20-26 eV range. This resonance induces a phase jump in the harmonic emission, a switch in the polarization state and different dynamical responses to molecular vibrations. This study demonstrates a method for extending high-harmonic spectroscopy to polyatomic molecules, where complex attosecond dynamics are expected.

• 出版日期2015-1
• 单位中国地震局