title: Energy localization and shape transformations in semiflexible polymer rings.
abstract: Shape transformations in driven and damped molecular chains are considered. Closed chains of weakly coupled molecular subunits under the action of spatially homogeneous time-periodic external field are studied. The coupling between the internal excitations and the bending degrees of freedom of the chain modifies the local bending rigidity of the chain. In the absence of driving the array takes a circular shape. When the energy pumped into the system exceeds some critical value the chain undergoes a nonequilibrium phase transition: The circular shape of the aggregate becomes unstable and the chain takes the shape of an ellipse or, in general, of a polygon. The excitation energy distribution becomes spatially nonuniform: It localizes in such places where the chain is more flat. The weak interaction of the chain with a flat surface restricts the dynamics to a flat manifold.
authors.affiliation: Bogolyubov Institute for Theoretical Physics, Metrologichna Street 14 B, 03143 Kiev, Ukraine.
authors.forename: Yu B
authors.initials: YB
authors.lastname: Gaididei
authors.affiliation: Grupo de Física No Lineal, Universidad de Sevilla, ETSI Informática, A. Reina Mercedes s/n, E-41012 Sevilla, Spain.
authors.forename: J F R
authors.initials: JF
authors.lastname: Archilla
authors.affiliation: Instituto de Investigación para la Gestión Integrada de las Zonas Costeras, Universidad Politécnica de Valencia, Paranimf 1, E-46730 Grao de Gandia, Spain.
authors.forename: V J
authors.initials: VJ
authors.lastname: Sánchez-Morcillo
authors.affiliation: Department of Applied Mathematics and Statistics, University of the Basque Country, E-48080 Bilbao, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Gorria