Disentangling conical intersection and coherent molecular dynamics in methyl bromide with attosecond transient absorption spectroscopy

Henry Timmers; Xiaolei Zhu; Zheng Li; Yuki Kobayashi; Mazyar Sabbar; Maximilian Hollstein; Maurizio Reduzzi; Todd J Martínez; Daniel M Neumark; Stephen R Leone

doi:10.1038/s41467-019-10789-7

Disentangling conical intersection and coherent molecular dynamics in methyl bromide with attosecond transient absorption spectroscopy

Nat Commun. 2019 Jul 16;10(1):3133. doi: 10.1038/s41467-019-10789-7.

Authors

Henry Timmers¹, Xiaolei Zhu^{2

3}, Zheng Li^{2

3

4

5}, Yuki Kobayashi¹, Mazyar Sabbar¹, Maximilian Hollstein⁶, Maurizio Reduzzi¹, Todd J Martínez^{2

3}, Daniel M Neumark^{1

7}, Stephen R Leone^{8

9

10}

Affiliations

¹ Department of Chemistry, University of California, Berkeley, CA, 94720, USA.
² Department of Chemistry and The PULSE Institute, Stanford University, Stanford, CA, 94305, USA.
³ SLAC Linear Accelerator Laboratory, Menlo Park, CA, 94025, USA.
⁴ Max Planck Institute for the Structure and Dynamics of Matter, 22761, Hamburg, Germany.
⁵ Department of Physics, Peking University, 100871, Beijing, China.
⁶ Department of Physics, University of Hamburg, 20355, Hamburg, Germany.
⁷ Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
⁸ Department of Chemistry, University of California, Berkeley, CA, 94720, USA. srl@berkeley.edu.
⁹ Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. srl@berkeley.edu.
¹⁰ Department of Physics, University of California, Berkeley, CA, 94720, USA. srl@berkeley.edu.

Abstract

Attosecond probing of core-level electronic transitions provides a sensitive tool for studying valence molecular dynamics with atomic, state, and charge specificity. In this report, we employ attosecond transient absorption spectroscopy to follow the valence dynamics of strong-field initiated processes in methyl bromide. By probing the 3d core-to-valence transition, we resolve the strong field excitation and ensuing fragmentation of the neutral σ* excited states of methyl bromide. The results provide a clear signature of the non-adiabatic passage of the excited state wavepacket through a conical intersection. We additionally observe competing, strong field initiated processes arising in both the ground state and ionized molecule corresponding to vibrational and spin-orbit motion, respectively. The demonstrated ability to resolve simultaneous dynamics with few-femtosecond resolution presents a clear path forward in the implementation of attosecond XUV spectroscopy as a general tool for probing competing and complex molecular phenomena with unmatched temporal resolution.

Abstract

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