Clusters of exceptional points for a laser control of selective vibrational transfer

Abstract

When a molecule is exposed to a laser field, all field-free vibrational states become resonances, with complex quasienergies calculated using Floquet theory. There are many ways to produce the coalescences of pairs of such quasienergies, with appropriate wavelength-intensity choices which define exceptional points (EP) in the laser parameter plane. We dress for the molecular ion H2+ an exhaustive map of these exceptional points which appear in clusters. Such clusters can be used to define several vibrational transfer scenarios implying more than a single exceptional point, exchanging single or multiple vibrational quanta. The ultimate goal is molecular vibrational cooling by transferring an initial (thermal, for instance) population on a final (ground, for instance) single vibrational state.