560 research outputs found
Improved Effective Range Expansion for Casimir-Polder potential
We study the effective range expansion of scattering on a real Casimir-Polder
potential. We use Liouville transformations which transform the potential
landscape while preserving the reflection and transmission amplitudes. We
decompose the scattering calculation in two more elementary problems, one for
the homogeneous 1/z^4 potential and the other one for the correction to this
idealization. We use the symmetries of the transformed problem and the
properties of the scattering matrices to derive an improved effective range
expansion leading to a more accurate expansion of scattering amplitudes at low
energy
Casimir torque between nanostructured plates
We investigate in detail the Casimir torque induced by quantum vacuum
fluctuations between two nanostructured plates. Our calculations are based on
the scattering approach and take into account the coupling between different
modes induced by the shape of the surface which are neglected in any sort of
proximity approximation or effective medium approach. We then present an
experimental setup aiming at measuring this torque.Comment: 7 pages, 7 figure
Fluctuations of the Casimir potential above a disordered medium
We study the statistical fluctuations of the Casimir potential felt by an
atom approaching a dielectric disordered medium. Starting from a microscopic
model for the disorder, we calculate the variance of potential fluctuations in
the limit of a weak density of heterogeneities. We show that fluctuations are
essentially governed by scattering of the radiation on a single heterogeneity,
and discuss in which limits they become larger than the average value predicted
by effective medium theory. Finally, for denser disorder we show that multiple
scattering processes become relevant.Comment: 9 pages, 5 figure
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