Lecture R. Esquivel-Sirvent
|05 november 2008||FWN-Building 5113.0202, Nijenborgh 4, 9747 AG, Groningen|
|Speaker:||Prof. R. Esquivel-Sirvent|
|Affiliation:||Instituto de Fisica, Universidad Nacional Autonoma de Mexico|
|Title:||Alternatives to the Drude and Plasma models in Casimir force calculations|
|Date:||Wed Nov 5, 2008|
|Telephone:||+31 50 363 4272|
The mid 90’s mark the beginning of the modern, high precision experiments of the Casimir force leading to new research in the role of realistic dielectric properties of materials . From the simple Drude and plasma models, to tabulated data and corrections such as spatial dispersion and surface roughness have been consider in the literature. The use of the Drude model has cause some controversies, since according to some authors the use of this model and the Lifshitz expression for the Casimir energy results in a violation of Nerst heat theorem. However, the plasma model does not give an adequate description of the dielectric function of metals. In this talk we present alternatives to these two models. In particular, we will discuss the Drude-Smith model for Au thin films near the insulator-conductor transition that has been observed experimentally. The parameters needed to model the dielectric function such as the relaxation time, plasma frequency and the backscattering constant depend on the thickness of the film. The Casimir force decreases as the film thickness decreases until it reaches a minimum after which the force increases again. The minimum of the force coincides with the critical film thickness where a percolation conductor-insulator occurs.
Besides thin films, liquid metals deviate from the standard Drude behavior, we also present Casimir force calculations between liquid metals and Au.
|Laatst gewijzigd:||22 oktober 2012 14:30|