EXCITONIC-VIBRONIC COUPLED DIMER - SEPARATRIX STRUCTURE, REGULAR AND CHAOTIC BEHAVIOR OF THE SEMICLASSICAL DYNAMICS VERSUS FULL-QUANTUM EVOLUTION

The dynamical properties of the excitonic-vibronic coupled dimer are i nvestigated using a stepwise quantization and comparing the system evo lution in a semiclassical approximation using mixed quantum (exciton)- classical (oscillator) variables with the dynamics of the fully quanti zed description. It is shown how the nonlinear features of the phase s pace dynamics in the mixed description are reflected in the evolution of the state vector of the fully quantized system. In particular, it i s demonstrated that the separatrix structure and the signatures of reg ular and chaotic motion of the mixed description are present in the wa ve packet propagation and the time evolution of the fully quantized sy stem. (C) 1998 Elsevier Science B.V. All rights reserved.