Study of first-order interface localization-delocalization transition in thin Ising-films using Wang-Landau sampling

Abstract

Using extensive Monte Carlo simulations, we study the interface localization- delocalization transition of a thin Ising film with antisymmetric competing walls for a set of parameters where the transition is strongly first-order. This is achieved by estimating the density of states (DOS) of the model by means of Wang-Landau sampling (WLS) in the space of energy, using both, single-spin-flip as well as N-fold way updates. From the DOS we calculate canonical averages related to the configurational energy, like the internal energy, the specific heat, as well as the free energy and the entropy. By sampling microcanonical averages during simulations we also compute thermodynamic quantities related to magnetization like the reduced fourth order cumulant of the order parameter. We estimate the triple temperatures of infinitely large systems for three different film thicknesses via finite size scaling of the positions of the maxima of the specific heat, the minima of the cumulant and the equal weight criterion for the energy probability distribution. The wetting temperature of the semi-infinite system is computed with help of the Young equation. In the limit of large film thicknesses the triple temperatures are seen to converge towards the wetting temperature of the corresponding semi-infinite Ising model in accordance with standard capillary wave theory. We discuss the slowing down of WLS in energy space as observed for the larger film thicknesses and lateral linear dimensions. In case of WLS in the space of total magnetization we find evidence that the slowing down is reduced and can be attributed to persisting free energy barriers due to shape transitions.

15 pages, 15 figures, uses revtex4

References in corpus (12)

• An efficient, multiple range random walk algorithm to calculate the density of states
• Determining the density of states for classical statistical models: A random walk algorithm to produce a flat histogram
• Avoiding Boundary Effects in Wang-Landau Sampling
• Computing the Roughening Transition of Ising and Solid-On-Solid Models by BCSOS Model Matching
• Wetting and Capillary Condensation in Symmetric Polymer Blends: A comparison between Monte Carlo Simulations and Self-Consistent Field Calculations
• Flat Histogram Method of Wang-Landau and N-fold Way
• A symmetric polymer blend confined into a film with antisymmetric surfaces: interplay between wetting behavior and phase diagram
• Comparison of Monte Carlo Results for the 3D Ising Interface Tension and Interface Energy with (Extrapolated) Series Expansions
• A Determination of Interface Free Energies
• Interface localisation-delocalisation transition in a symmetric polymer blend: a finite-size scaling Monte Carlo study
• Finite size effects on the phase diagram of a binary mixture confined between competing walls
• Coupled Fluctuations near Critical Wetting

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