title: Fluctuation-induced interactions in nematics with disordered anchoring energy.
abstract: We examine fluctuation-induced (pseudo-Casimir) interactions in nematic liquid-crystalline films confined between two surfaces, where one of the surfaces imposes a strong homeotropic anchoring (ensuring a uniform mean director profile), while the other one is assumed to be a chemically disordered substrate exhibiting an annealed distribution of anchoring energies. We employ a saddle-point approximation to evaluate the free energy of interaction mediated between the two surfaces and investigate how the interaction force is influenced by the presence of disordered surface anchoring energy. It is shown that the disorder results in a renormalization of the effective surface anchoring parameter in a way that it leads to quantitative and qualitative changes (including a change of sign at intermediate inter-surface separations) in the pseudo-Casimir interaction force when compared with the interaction force in the absence of disorder.
authors.affiliation: Faculty of Physics, Kharazmi University, Karaj 31979-37551, Iran.
authors.forename: Fahimeh Karimi Pour
authors.initials: FK
authors.lastname: Haddadan
authors.forename: Ali
authors.initials: A
authors.lastname: Naji
authors.forename: Nafiseh
authors.initials: N
authors.lastname: Shirzadiani
authors.forename: Rudolf
authors.initials: R
authors.lastname: Podgornik