Danish Ph.D. School in Nonlinear Science

Sponsored by the Danish Research Academy

Soliton Modelling for Energy and Charge Transport in Molecular Systems
by A.V. Savin, Institute for Problems of Physics and Technology, Moscow, Russia
presently: as@imm.dtu.dk
and A.V. Zolotaryuk, Bogolyubov Institute for Theoretical Physics, Kyiv, Ukraine
e-mail: azolo@gluk.apc.org
presently: az@imm.dtu.dk

MIDIT-seminars 394 and 395
Thursday December 11, 1997 15.00 h and 16.00 h
at MIDIT, IMM Building 305, room 027

A.V. Zolotaryuk and A.V. Savin,
I. Polaron models: interaction of a quamtum quasi-particle with nonlinear lattices

Abstract: A survey on soliton models used to investigate transfers of vibrational energy and electrons in molecular chains is given. These models describe the following three transport mechanisms: (i) the self-trapping of an excess quantum quasi-particle by the acoustic and optical modes (Davydov's and Holstein's models), (ii) Capture and transfer of a quantum quasi-particle by the lattice (acoustic) soliton, (iii) capture and transport of a quantum quasi-particle by a topological soliton. Numerical methods for seeking moving soliton solutions are presented. Applications to biomolecular dynamics are briefly discussed.

A.V. Savin and A.V. Zolotaryuk,
II. Proton dynamics in hydrogen-bonded networks and soliton ratchets

Abstract: Applications for a description of the proton transport in quasi-one-dimensional hydrogen-bonded chains are presented. A two-component soliton model for proton transfers in such chains is derived and treated for the case when heavy ions of the background sublattice are allowed to move. Peculiar properties of soliton-velocity spectrum for this case are discussed. The two-dimensional topological solitons are treated on the basis of the nonlinear dynamical square ice model. The ratchet soliton motion that occurs in the one-dimensional kink-bearing family of models with an anisotropic spatial asymmetry of the on-site potential is also discussed.