On the vibron nature in the system of two parallel macromolecular chains: The influence of interchain coupling

Abstract

We studied the properties of the intramolecular vibrational excitation (vibron) at finite temperature in a system which consists of two parallel macromolecular chains. It was assumed that vibron interacts exclusively with dispersionless optical phonons and the whole system is considered to be in thermal equilibrium. Particular attention has been paid to the examination of the impact of the temperature and strength of the interchain coupling on the small polaron crossover. For that purpose we employed partial dressing method which enables the study of the degree of the phonon dressing of the vibron excitations in a wide area of system parameter space. We found that in the non-adiabatic regime the degree of dressing as a function of coupling constant continuously increases reflecting the smooth transition of the slightly dressed, practically free vibron, to a heavily dressed one: small polaron. As "adiabaticity" rises this transition becomes increasingly steeper, and finally, in the adiabatic limit, a discontinuous "jump" of the degree of dressing is observed. The interchain coupling manifests itself through the increase of the effective adiabatic parameter of the system.

On the vibron-polaron damping in quasi 1D macromolecular chains

“…1 and 2. Obtained results appear to be consistent with the predictions of our earlier work concerned with the vibron self-trapping in the alpha-helix and two parallel chain structures [14,18]. Briefly, we found that the system parameter space is divided on two characteristic areas: in the first area vibron dressing is a continuous function of the coupling constant S for fixed values of T and B.…”

Vibron Dressing in the Three Paralell Macromolecular Chain Structure

“…Earlier, the properties of both the intramolecular vibrational excitation (vibron) in a quasi 1D macro-molecular structure, and the case of two macromolecular chains. were studied in our papers [9][10][11], in part, within improved Holstein molecular crystal model [2,3,4]. There it was supposed that due to the vibron interaction with optical phonon modes, vibron form partially dressed small polaron states.…”

Temperature dependence of quantum correlations in 1D macromolecular chains

“…This minimization procedure is similar to that used in refs. [16][17][18] for the study of polaron dressing in various systems of molecular chains. The behavior of parameter δ for three different temperatures is shown in Fig.…”