Model simulation of coherent laser control of the ultrafast spin-flip dynamics of matrix-isolated Cl2

Starting from a diatomics-in-molecules Hamiltonian description of the valence states Of Cl-2 embedded in an argon matrix, classical trajectory simulations are utilized to establish a one-dimensional model for the photodissociation dynamics in three selected singlet and triplet states which is valid during approximately 150 fs after Franck-Condon excitations, i.e. before the Cl atoms approach the neighbouring Ar atoms. Using this one-dimensional model which describes the dynamics of the Cl-Cl bond length in the frozen argon lattice we carry out quantum dynamics simulations of the laser pulse control of the electronic spin with fermosecond time resolution and sub-Angstrom spatial localization by means of simultaneous excitation of wave packets on the singlet and triplet potential curves starting from a vibrational superposition state in the electronic ground state. It is shown that the latter can be prepared by a pump-dump pulse sequence. (c) 2006 Elsevier B.V. All rights reserved.