Matter-screened Casimir force and Casimir-Polder force in planar structures

Using a recently developed theory of the Casimir force (Raabe C and Welsch D-G 2005 Phys. Rev. A 71 013814), we calculate the force that acts on a plate in front of a planar wall and the force that acts on the plate in the case where the plate is part of matter that fills the space in front of the wall. We show that in the limit of a dielectric plate whose permittivity is close to unity, the force obtained in the former case reduces to the ordinary, i.e., unscreened Casimir-Polder force acting on isolated atoms. In the latter case, the theory yields the Casimir-Polder force that is screened by the surrounding matter.Comment: 11 pages, 1 figure -- published online at J. Opt. B on Nov 16 200

Markovian Master Equations: A Critical Study

We derive Markovian master equations of single and interacting harmonic systems in different scenarios, including strong internal coupling. By comparing the dynamics resulting from the corresponding Markovian master equations with exact numerical simulations of the evolution of the global system, we precisely delimit their validity regimes and assess the robustness of the assumptions usually made in the process of deriving the reduced dynamics. The proposed method is sufficiently general to suggest that the conclusions made here are widely applicable to a large class of settings involving interacting chains subject to a weak interaction with an environment.Comment: 40 pages, 14 figures, final versio

Reinforcement of Elastic Polymer Matrix Filled with Ultrafine Particles

The nanofiller of noble metal may modify the properties of the polymer- noble metal composite even if the concentration of the metal nanoparticles is very low. The aim of this paper is to study the influence of colloidal particles in nanocomposites. For our studies we have selected polymethyl methacrylate-palladium nanocomposite. It is shown that the effective radius of the immobilised matrix environment is much greater than the radius of the palladium particles. Due to the binding of the matrix polymer and the palladium surface some volume of the surrounding matrix becomes immobilised giving rise to the effective increase in the size of the palladium filler. The analysis of a few models of nanocomposites used for interpretation of the mechanical properties has also been presented