Quantum‐phase and information‐entropy dynamics of dimers interacting with a single‐mode coherent field: The difference between one‐ and two‐exciton models

Abstract

AbstractWe develop a numerically exact approach to the quantum‐phase and information‐entropy dynamics of a molecular aggregate interacting with quantized fields. It is well known that a peculiar quantum nature, i.e., collapses and revivals, is observed in monomer and noninteracting aggregate models. In this article, we investigate the intermolecular interaction effects on the collapse‐revival behavior using several dimer models (composed of two‐state monomers with different intermolecular distances) interacting with a single‐mode coherent photon field. The intermolecular interaction is taken into account by using the dipole‐dipole interaction. Also, one‐ and two‐exciton dimer models are considered in order to elucidate the exciton contributions to collapse‐revival behavior. This quantum behavior is analyzed from the viewpoint of the dynamics of Pegg–Barnett photon‐phase and information‐entropy of dimers, which closely relate to the time evolution of quantum coherency between the ground and the excited dimer states and the degree of the entanglement between dimer and photon, respectively. It is found that the intermolecular interaction and the two‐exciton generation provide remarkable changes in the collapse‐revival behavior through their significant influence on the quantum‐phase dynamics and the photon‐dimer entanglement. From the dimer entropy dynamics, intermediate intermolecular interaction is found to cause the momentary decrease in the photon‐dimer correlation in the early time region. This feature leads to the enhancement of off‐diagonal density (quantum coherency) between two dimers. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001