Critical Casimir forces in a magnetic system: An experimental protocol

摘要

We numerically test an experimentally realizable method for the extraction ofthe critical Casimir force based on its thermodynamic definition as thederivative of the excess free energy with respect to system size. Free energydifferences are estimated for different system sizes by integrating the orderparameter along an isotherm. The method could be developed for experiments onmagnetic systems and could give access to the critical Casimir force for anyuniversality class. By choosing an applied field that opposes magnetic orderingat the boundaries, the Casimir force is found to increase by an order ofmagnitude over zero-field results.