Semiflexible Chains under Tension

Дата и время публикации : 1996-09-13T23:46:33Z

Авторы публикации и институты :
B. -Y. Ha
D. Thirumalai

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 14 pages, 1 figure available upon request, submitted to J. Chem. Phys
Первичная категория: cond-mat

Все категории : cond-mat

Краткий обзор статьи: A functional integral formalism is used to derive the extension of a stiff chain subject to an external force. The force versus extension curves are calculated using a meanfield approach in which the hard constraint $u^2(s)=1$ is replaced by a global constraint $ < u^2(s) > = 1$ where $ u(s)$ is the tangent vector describing the chain and $s$ is the arc length. The theory “quantitatively” reproduces the experimental results for DNA that is subject to a constant force. We also treat the problems of a semiflexible chain in a nematic field. In the limit of weak nematic field strength our treatment reproduces the exact results for chain expansion parallel to the director. When the strength of nematic field is large, a situation in which there are two equivalent minima in the free energy, the intrinsically meanfield approach yields incorrect results for the dependence of the persistence length on the nematic field.

Category: Physics