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-Hückel theory. The standard Odijk, Skolnick, and Fixman (OSF) theory suggests l_e∝r_s², while some variational theories and some computer simulations suggest l_e∝r_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∝r_s². The linear charge density of the PE, which enters in the coefficient of this dependence is properly renormalized to take into account local fluctuations.