Critical Casimir forces between planar and crenellated surfaces. (12th May 2015)

• Record Type: Journal Article
• Authors: Tröndle, M; Harnau, L; Dietrich, S
• Is Part Of: Journal of physics. Volume 27:Number 21(2015)
• Publication Date: 2015-05-12
• Subjects: fluctuation-induced forces -- structured substrates -- confined fluids; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/27/21/214006
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: We study critical Casimir forces between planar walls and geometrically structured substrates within mean-field theory. As substrate structures, crenellated surfaces consisting of periodic arrays of rectangular crenels and merlons are considered. Within the widely used proximity force approximation, both the top surfaces of the merlons and the bottom surfaces of the crenels contribute to the critical Casimir force. However, for such systems the full, numerically determined critical Casimir forces deviate significantly from the pairwise addition formalism underlying the proximity force approximation. A first-order correction to the proximity force approximation is presented in terms of a step contribution arising from the critical Casimir interaction between a planar substrate and the right-angled steps of the merlons consisting of their upper and lower edges as well as their sidewalls.