In this paper, we considered a molecular structure that consists of a molecular chain and an additional molecule (donor or acceptor) that can inject (or remove) single excitation (vibron, electron, etc.) onto the molecular chain. We assumed that the excitation forms a self-trapped state due to the interaction with mechanical oscillations of the chain structure elements.
View Article and Find Full Text PDFJ Phys Condens Matter
July 2009
The features of the moving large polaron are investigated within Holstein's molecular crystal model. The necessity to account for the phonon dispersion is emphasized and its impact on polaron properties is examined in detail. It was found that the large polaron dynamics is described by the nonlocal nonlinear Schrödinger equation.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
January 2006
The validity of the recently proposed tentative improvement of the Davydov theory of intramolecular vibrational transfer is discussed. It is shown that it contains a few principal shortcomings and cannot be a sound ground for studies of the transport processes in molecular systems.
View Article and Find Full Text PDFPhys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics
July 1999
The Fokker-Planck equation for multivibron solitons interacting with lattice vibrations in a molecular chain has been derived by means of the nonequilibrium statistical operator method. It was shown that a soliton undergoes diffusive motion characterized by two substantially different diffusion coefficients. The first one corresponds to the ordinary (Einsteinian or dissipative) diffusion and characterizes the soliton Brownian motion, while the second one corresponds to the anomalous diffusion connected with frictionless displacement of the soliton center of mass coordinate due to the interaction with phonons.
View Article and Find Full Text PDFPhys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics
June 2000
Dynamics and the stability of the multivibron solitons in molecular chains have been examined by means of the perturbation method based upon the inverse scattering transform. We demonstrate that due to the coupling with phonons the soliton radiates energy which causes its slowing down and gradual decay of its amplitude. It was shown that the soliton lifetime depends strongly on temperature and the values of the basic physical parameters of the system.
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