arXiv subjects

R. Esquivel

Publications and source records attributed to R. Esquivel.

3 recordsLinked to original sources

arXiv2005

Non-local thin films in Casimir force calculations

he Casimir force is calculated between plates with thin metallic coating. Thin films are described with spatially dispersive (nonlocal) dielectric functions. For thin films the nonlocal effects are more relevant than for half-spaces. However, it is shown that even for film thickness smaller than the mean free path for electrons, the difference between local and nonlocal calculations of the Casimir force is of the order of a few tenths of a percent. Thus the local description of thin metallic films is adequate within the current experimental precision and range of separations.

quant-ph↗

arXiv2004

Correction to the Casimir force due to the anomalous skin effect

The surface impedance approach is discussed in connection with the precise calculation of the Casimir force between metallic plates. It allows to take into account the nonlocal connection between the current density and electric field inside of metals. In general, a material has to be described by two impedances $Z_{s}(ω,q)$ and $Z_{p}(ω,q)$ corresponding to two different polarization states. In contrast with the approximate Leontovich impedance they depend not only on frequency $ω$ but also on the wave vector along the plate $q$. In this paper only the nonlocal effects happening at frequencies $ω<ω_{p}$ (plasma frequency) are analyzed. We refer to all of them as the anomalous skin effect. The impedances are calculated for the propagating and evanescent fields in the Boltzmann approximation. It is found that $Z_p$ significantly deviates from the local impedance as a result of the Thomas-Fermi screening. The nonlocal correction to the Casimir force is calculated at zero temperature. This correction is small but observable at small separations between bodies. The same theory can be used to find more significant nonlocal contribution at $ω\simω_p$ due to the plasmon excitation.

quant-ph↗

arXiv2003

Exact results for Casimir forces using Surface Impedance: Nonlocal Media

We show that exact results are obtained for the calculation of Casimir forces between arbitrary materials using the concept of surface impedances, obtaining in a trivial way the force in the limit of perfect conductors and also Lifshitz formula in the limit of semi-infinite media. As an example we present a full and rigorous calculation of the Casimir force between two metallic half-spaces described by a hydrodynamic nonlocal dielectric response.

quant-ph↗