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

Abstract

AbstractWe 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.