EXCITONIC - VIBRONIC COUPLED DIMERS - A DYNAMIC APPROACH

The dynamical properties of exciton transfer coupled to polarization v ibrations in a two site system are investigated in detail. A fixed poi nt analysis of the full system of Bloch - oscillator equations represe nting the coupled excitonic - vibronic flow is performed. For over-cri tical polarization a bifurcation converting the stable bonding ground state to a hyperbolic unstable state which is basic to the dynamical p roperties of the model is obtained. The phase space of the system is g enerally of a mixed type: Above bifurcation chaos develops starting fr om the region of the hyperbolic state and spreading with increasing en ergy over the Bloch sphere leaving only islands of regular dynamics. T he behaviour of the polarization oscillator accordingly changes from r egular to chaotic.