Femtosecond Symmetry Breaking and Coherent Relaxation of Methane Cations at the Carbon K-Edge

Abstract

Understanding the relaxation pathways of photoexcited molecules is essential to gain atomistic level insight into photochemistry. Herein, we perform a time-resolved study of ultrafast molecular symmetry breaking via geometric relaxation (Jahn-Teller distortion) on the methane cation. Attosecond transient absorption spectroscopy with soft X-rays at the carbon K-edge reveals that the distortion occurs within $10\pm 2$ femtoseconds after few-femtosecond strong-field ionization of methane. The distortion activates coherent oscillations in the scissoring vibrational mode of the symmetry broken cation, which are detected in the X-ray signal. These oscillations are damped within $58\pm 13$ femtoseconds, as vibrational coherence is lost with the energy redistributing into lower-frequency vibrational modes. This study completely reconstructs the molecular relaxation dynamics of this prototypical example and opens new avenues for exploring complex systems.

References in corpus (5)

• Highly Accurate Prediction of Core Spectra of Molecules at Density Functional Theory Cost: Attaining sub eV Error from a Restricted Open-Shell Kohn-Sham Approach
• Femtosecond Symmetry Breaking and Coherent Relaxation of Methane Cations at the Carbon K-Edge
• Accurate prediction of core-level spectra of radicals at density functional theory cost via square gradient minimization and recoupling of mixed configurations
• Coherent electronic-vibrational dynamics in deuterium bromide probed via attosecond transient absorption spectroscopy
• Transient grating spectroscopy of SF6 molecular vibrations

Cited by in corpus (8)

• Femtosecond Symmetry Breaking and Coherent Relaxation of Methane Cations at the Carbon K-Edge
• Dynamic Jahn-Teller effect in the strong spin-orbit coupling regime
• Non-Adiabatic Electronic and Vibrational Ring-Opening Dynamics resolved with Attosecond Core-Level Spectroscopy
• Prediction of Photodynamics of 200 nm Excited Cyclobutanone with Linear Response Electronic Structure and Ab Initio Multiple Spawning
• Generalization of one-center non orthogonal configuration interaction singles to open shell singlet reference states: Theory and application to valence-core pump-probe states in acetylacetone
• Electronic-vibrational dynamics and coherence in x-ray transient absorption of N2+ induced by strong-field ionization
• Measurement of Coherent Vibrational Dynamics with X-ray Transient Absorption Spectroscopy Simultaneously at the Carbon K- and Chlorine L${}_{2,3}$- Edges
• Elucidating Many-Body Effects in Molecular Core Spectra through Real-Time Approaches: Efficient Classical Approximations and a Quantum Perspective