Universal scaling functions of critical Casimir forces obtained by Monte Carlo simulations

TL;DR

This paper uses Monte Carlo simulations to compute universal scaling functions of critical Casimir forces near critical points in three-dimensional systems, providing results relevant for experiments and theory.

Contribution

It introduces a novel integration-based approach to accurately determine the universal scaling functions of critical Casimir forces in 3D systems.

Findings

Computed universal scaling functions for various surface universality classes.

Compared simulation results with experimental data on fluid wetting films.

Validated the approach against existing theoretical predictions.

Abstract

Effective Casimir forces induced by thermal fluctuations in the vicinity of bulk critical points are studied by means of Monte Carlo simulations in three-dimensional systems for film geometries and within the experimentally relevant Ising and XY universality classes. Several surface universality classes of the confining surfaces are considered, some of which are relevant for recent experiments. A novel approach introduced previously EPL 80, 60009 (2007), based inter alia on an integration scheme of free energy differences, is utilized to compute the universal scaling functions of the critical Casimir forces in the critical range of temperatures above and below the bulk critical temperature. The resulting predictions are compared with corresponding experimental data for wetting films of fluids and with available theoretical results.