paper

Critical free energy and Casimir forces in rectangular geometries

arXiv:1012.5955 · doi:10.1103/PhysRevE.84.021108

Abstract

We study the critical behavior of the free energy and the thermodynamic Casimir force in a block geometry in dimensions with aspect ratio above, at, and below on the basis of the O symmetric lattice model with periodic boundary conditions (b.c.). We consider a simple-cubic lattice with isotropic short-range interactions. Exact results are derived in the large - limit describing the geometric crossover from film () over cubic to cylindrical () geometries. For , three perturbation approaches are presented that cover both the central finite-size regime near for and the region outside the central finite-size regime well above and below for arbitrary . At bulk of isotropic systems with periodic b.c., we predict the critical Casimir force in the vertical direction to be negative (attractive) for a slab (), positive (repulsive) for a rod (), and zero for a cube . We also present extrapolations to the cylinder limit () and to the film limit () for and . Our analytic results for finite-size scaling functions in the minimal renormalization scheme at fixed dimension agree well with Monte Carlo data for the three-dimensional Ising model by Hasenbusch for and by Vasilyev et al. for above, at, and below .

23 pages, 14 figures

References in corpus (20)

Cited by in corpus (13)