Conical Intersection Dynamics in NO 2 Probed by Homodyne High-Harmonic Spectroscopy

H. Wörner (1, 2, 3) , J. Bertrand (1, 2) , B. Fabre (4) , J. Higuet (4) , H. Ruf (4) , A. Dubrouil (4) , S. Patchkovskii (1, 2) , M. Spanner (1, 2) , Y. Mairesse (4) , V. Blanchet (5, 6) , E. Mével (4) , E. Constant (4) , P. Corkum (1, 2) , D. Villeneuve (1, 2)

1 Joint Attosecond Science Laboratory
2 University of Ottawa [Ottawa]
3 ETH-LPC - Laboratorium für Physikalische Chemie
4 CELIA - Centre d'Etudes Lasers Intenses et Applications
5 LCAR - Laboratoire Collisions Agrégats Réactivité
6 Femto (LCAR)

Conical intersections play a crucial role in the chemistry of most polyatomic molecules, ranging from the simplest bimolecular reactions to the photostability of DNA. The real-time study of the associated electronic dynamics poses a major challenge to the latest techniques of ultrafast measurement. We show that high-harmonic spectroscopy reveals oscillations in the electronic character that occur in nitrogen dioxide when a photoexcited wave packet crosses a conical intersection. At longer delays, we observe the onset of statistical dissociation dynamics. The present results demonstrate that high-harmonic spectroscopy could become a powerful tool to highlight electronic dynamics occurring along nonadiabatic chemical reaction pathways.

Domaines: Physique [physics]

H. Wörner, J. Bertrand, B. Fabre, J. Higuet, H. Ruf, et al.. Conical Intersection Dynamics in NO 2 Probed by Homodyne High-Harmonic Spectroscopy. Science, 2011, 334 (6053), pp.208-212. ⟨10.1126/science.1208664⟩. ⟨hal-03495164⟩