Issue Europhys. Lett. Volume 57, Number 5, March 2002 Page(s) 697 - 703 Section Condensed matter: structure, mechanical and thermal properties DOI 10.1209/epl/i2002-00519-4

DOI: 10.1209/epl/i2002-00519-4


Europhys. Lett., 57 (5) , pp. 697-703 (2002)

Transport of localized vibrational energy in biopolymer models with rigidity

G. P. Tsironis, M. Ibañes and J. M. Sancho

Department d'Estructura i Constituents de la Matèria, Universitat de Barcelona Diagonal 647, E-08028 Barcelona, Spain

(Received 22 March 2001; accepted in final form 29 November 2001)

Abstract
We address energy localization and transport in discrete curvilinear chains that model biopolymers. We use a one-dimensional modified Fermi-Pasta-Ulam model that describes approximately dynamics in curved polymers with rigid angles and only first-neighbor interactions and investigate the existence of localized energy in the form of discrete breathers. We show that breathers propagate freely in low curvature regions of the chain while there is a critical curvature above which breathers rebounce elastically without however loosing their integrity. Furthermore, breathers traverse hairpin geometries that model -sheet bends, adapting to the local curvature while modifying their propagation speed in the curved segment. These features are stable against small local polymer angle deformations and generally persist in the nonrigid angle chain.

PACS
63.20.Ry - Anharmonic lattice modes.
63.20.Pw - Localized modes.
36.20.-r - Macromolecules and polymer molecules.


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