Coil-bridge transition and Monte Carlo simulation of a stretched polymer

The structure of the system consisting of a grafted self-avoiding polymer chain attracted to the surface layer of a flat wall at a distance away by a short-ranged force is investigated. A first-order transition is determined between the coil state at a low attraction energy and the bridge state at a high attraction energy. The transition properties of the system are obtained by a Monte Carlo simulation, which uses the inverse density of states as the transition weight and is reweighted back to a canonical ensemble. The determination of the density of states follows a revised Wang-Landau procedure in which the center-of-mass distance from the grafted site is used as the variable. Scaling arguments are also given for the observed numerical results.