Breakdown of Born‐Oppenheimer Approximation as a Physical Mechanism for Ultrafast Hydrogen Migrations in Strong Laser Driven Molecules

Abstract

We propose a physical mechanism based on breakdown of the Born-Oppenheimer approximation to rationalize the ultrafast hydrogen migration in strong laser driven isomerization reactions. A three nuclei (proton, donor, and acceptor) model is employed to develop a three step solution scheme. The proton-donor Coulomb repulsion is shown to be responsible for the high proton mobility. We identify a proton tunneling process and use the Keldysh-Faisal-Reiss theory to calculate the tunneling probability. The effect of laser parameters (intensity, frequency, polarization, and pulse duration) has been studied and found to be consistent with recent experiments.