Persistence length of a polyelectrolyte in salty water: Monte Carlo study

We address the long standing problem of the dependence of the electrostatic persistence length l(e) of a flexible polyelectrolyte (PE) on the screening length r(s) of the solution within the linear Debye-Huckel theory. The standard Odijk, Skolnick, and Fixman (OSF) theory suggests l(e)proportional tor(s)(2), while some variational theories and some computer simulations suggest l(e)proportional tor(s). In this paper, we use Monte Carlo simulations to study the conformation of a simple polyelectrolyte. Using four times longer PEs than in previous simulations and refined methods for the treatment of the simulation data, we show that the results are consistent with the OSF dependence l(e)proportional tor(s)(2). The linear charge density of the PE, which enters in the coefficient of this dependence is properly renormalized to take into account local fluctuations.