Controlling the Time Evolution of Electron-Nuclei Entanglement for Steering Vibronic Coherences Dynamics Induced by Short 1–2 fs Optical Pulses

Atto pulses allow controlling the charge migration and the spatio-temporal beating of the electronic density on a purely electronic time scale by tailoring the parameters of the pump pulse to excite specific electronic coherences. As the nuclei begin to move, the electronic and nuclear motions are entangled and the engineered electronic coherences can be usefully exploited for steering the vibronic density to specific products through the network of non adiabatic interactions. Three recent examples for which we demonstrate such a control by fully quantum dynamical computations are discussed. Two diatomic molecules, LiH and N2 excited by a 2 fs deep UV pulse and the ultrafast structural Jahn-Teller rearrangement in CH4+. The entanglement between electronic and nuclear degrees of freedom arises from the optical excitation and from non adiabatic coupling induced by the nuclear motion. We provide insight of the coherence control mechanism by analyzing the time evolution of the entanglement using a singular valued decomposition (SVD) of the matricized wave function.