Phase- and intensity-dependence of ultrafast dynamics in hydrocarbon molecules in few-cycle laser fields

Abstract

In strong laser fields, sub-femtosecond control of chemical reactions with the carrier-envelope phase (CEP) becomes feasible. We have studied the control of reaction dynamics of acetylene and allene in intense few-cycle laser pulses at 750 nm, where ionic fragments are recorded with a reaction microscope. We find that by varying the CEP and intensity of the laser pulses it is possible to steer the motion of protons in the molecular dications, enabling control over deprotonation and isomerization reactions. The experimental results are compared to predictions from a quantum dynamical model, where the control is based on the manipulation of the phases of a vibrational wave packet by the laser waveform. The measured intensity dependence in the CEP-controlled deprotonation of acetylene is well captured by the model. In the case of the isomerization of acetylene, however, we find differences in the intensity dependence between experiment and theory. For the isomerization of allene, an inversion of the CEP-dependent asymmetry is observed when the intensity is varied, which we discuss in light of the quantum dynamical model. The inversion of the asymmetry is found to be consistent with a transition from non-sequential to sequential double ionization.

arXiv comment15 pages, 8 figures

References in corpus (9)

• Attosecond-recollision-controlled selective fragmentation of polyatomic molecules
• Unitary theory of laser Carrier-Envelope Phase effects
• Two-Color Strong-Field Photoelectron Spectroscopy and the Phase of the Phase
• Steering proton migration in hydrocarbons using intense few-cycle laser fields
• Coherent control at its most fundamental: CEP-dependent electron localization in photodissoziation of a H2+ molecular ion beam target
• Carrier-envelope phase control over pathway interference in strong-field dissociation of H${}_2^{+}$
• Carrier envelope phase effects in ultrafast, strong-field ionization dynamics of multielectron systems: Xe and CS${}_2$
• Enhancing the intense field control of molecular fragmentation
• Carrier-Envelope-Phase Dependent Dissociation of Hydrogen

Cited by in corpus (1)

• Revealing laser-coherent electron features using phase-of-the-phase spectroscopy