Semiflexible polymers: dependence on ensemble and boundary orientations.
We show that the mechanical properties of a worm-like-chain (WLC) polymer, of contour length L and persistence length lambda such that t=L/lambda approximately O(1), depend both on the ensemble and the constraint on end orientations. In the Helmholtz ensemble, multiple minima in the free energy near t=4 persists for all kinds of orientational boundary conditions. The qualitative features of projected probability distribution of end-to-end vector depend crucially on the embedding dimensions. A mapping of the WLC model, to a quantum particle moving on the surface of a unit sphere, is used to obtain the statistical and mechanical properties of the polymer under various boundary conditions and ensembles. The results show excellent agreement with Monte Carlo simulations.
Chaudhuri
Debasish
D
Department of Biological Physics, Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany. debc@mpipks-dresden.mpg.de