Research On Casimir Effect Between Anisotropic Metamaterials Slabs

Casimir effect is a macroscopic quantum effect that results from the change of boundary condition in the vacuum electromagnetic field. It has a very significant status in the domain of physics, and especially has an important effect on micrometer and nanometer mechanical system. Now there are mainly three methods to deal with Casimir effect, which are respectively based on the macroscopic theory of Lifshitz method, surface mode summation method and Maxwell stress tensor method. In recent years, people begin to research Casimir effect between dielectric slabs when anisotropy and frequency dispersion of permittivity and permeability of the material are concerned. As a result, this study will bring about some novel physical phenomena. As new-type materials metamaterials are jointly prepared from microstructure and nanostructure. They still satisfy the Maxwell equations set, and are endowed with some peculiar electromagnetic properties. Thus people pay more attention to the metamaterials. Real metamaterials are dispersive, the values of the characteristic frequencies in dispersion relation affect electromagnetic properties, especially reflection property of material. Therefore, it will make a great impact on Casimir effect when metamaterials are taken as boundary materials.We adopt Maxwell stress tensor method to calculate Casimir effect between metamaterials slabs when anisotropy and dispersion property of material are taken into consideration. Under the circumstances, the control of strength of Casimir effect is discussed, besides, we also show how to generate repulsive Casimir force. The main research work is as follows:Firstly, Casimir effect between two dielectric slabs is derived by using Maxwell stress tensor method, then the calculation for the Casimir force is expanded to anisotropic metamaterials, which is on the basis of the computing theory and analytic property of the integrand for Casimir force between dielectric slabs in the complex plane. Because the integral formula for Casimir force is involved with reflection coefficient of material slabs. Regarding this question, we consider that optical axis of material is respectively perpendicular and parallel to slab surface, and then work out the reflection coefficient. Accordingly, the Casimir force that is convenient for numerical calculation is obtained. Subsequently, the Casimir effect between two uniaxial crystal slabs and between two anisotropic left-handed material slabs is discussed in detail. We analyze the change of Casimir effect for the two cases, which depends on slab separation, material characteristic frequencies of dispersion and the orientations of optical axis, the final simulation results show that strength of Casimir effect is influenced by slab separation and material properties. Casimir force is greatly restrained at short distances, however the inhibitory action will be gradually weakened with the increasing slab separation. Thus, we can consider how to avoid adhesion, which may exist in micromechanical component at short distances. In addition, when there are different values of the parameters and orientations of optical axis of material, the magnitude of Casimir force will make a difference. Consequently, the Casimir effect between metamaterials slabs can be controlled effectively by adjusting the slab separation and material properties.Finally, the repulsive Casimir effect is also analyzed in following three situations: the structure of two anisotropic left-handed material slabs, the structure of electric single-negative material and magnetic single-negative material and the structure of metal plate and anisotropic left-handed material. Only when two slabs have different electromagnetic properties will the repulsive Casimir effect appear.