28 research outputs found
Exploring the quantum vacuum with cylinders
We review recent work on the Casimir interaction energy between cylindrical
shells. We include proposals for future experiments involving cylinders, such
us a null experiment using quasi-concentric cylinders, a cylinder in front a
conducting plate, and a cylindrical version of the rack and pinion powered by
Casimir lateral force. We also present an exact formula for the theoretical
evaluation of the vacuum interaction energy between eccentric cylindrical
shells, and describe improved analytical and numerical evaluations for the
particular case of concentric cylinders.Comment: 11 pages, 6 figures, Proceedings of QFEXT07. To be published in J.
Phys.
Casimir interaction between two concentric cylinders at nonzero temperature
We study the finite temperature Casimir interaction between two concentric
cylinders. When the separation between the cylinders is much smaller than the
radii of the cylinders, the asymptotic expansions of the Casimir interaction
are derived. Both the low temperature and the high temperature regions are
considered. The leading terms are found to agree with the proximity force
approximations. The low temperature leading term of the temperature correction
is also computed and it is found to be independent of the boundary conditions
imposed on the larger cylinder.Comment: 6 pages, 1 figur
Hertz potentials approach to the dynamical Casimir effect in cylindrical cavities of arbitrary section
We study the creation of photons in resonant cylindrical cavities with time
dependent length. The physical degrees of freedom of the electromagnetic field
are described using Hertz potentials. We describe the general formalism for
cavities with arbitrary section. Then we compute explicitly the number of TE
and TM motion-induced photons for cylindrical cavities with rectangular and
circular sections. We also discuss the creation of TEM photons in non-simply
connected cylindrical cavities.Comment: 13 pages, 3 figures, revtex
Exact Casimir interaction between eccentric cylinders
The Casimir force is the ultimate background in ongoing searches of
extra-gravitational forces in the micrometer range. Eccentric cylinders offer
favorable experimental conditions for such measurements as spurious
gravitational and electrostatic effects can be minimized. Here we report on the
evaluation of the exact Casimir interaction between perfectly conducting
eccentric cylinders using a mode summation technique, and study different
limiting cases of relevance for Casimir force measurements, with potential
implications for the understanding of mechanical properties of nanotubes.Comment: 5 pages, 4 figure
Casimir energy between media-separated cylinders: the scalar case
We derive exact expressions for the Casimir scalar interaction energy between
media-separated eccentric dielectric cylinders and for the media-separated
cylinder-plane geometry using a mode-summation approach. Similarly to the
electromagnetic Casimir-Lifshitz interaction energy between fluid-separated
planar plates, the force between cylinders is attractive or repulsive depending
on the relative values of the permittivities of the three intervening media.Comment: New figure and discussion about the integration contour in the
complex plan
Thermal and dissipative effects in Casimir physics
We report on current efforts to detect the thermal and dissipative
contributions to the Casimir force. For the thermal component, two experiments
are in progress at Dartmouth and at the Institute Laue Langevin in Grenoble.
The first experiment will seek to detect the Casimir force at the largest
explorable distance using a cylinder-plane geometry which offers various
advantages with respect to both sphere-plane and parallel-plane geometries. In
the second experiment, the Casimir force in the parallel-plane configuration is
measured with a dedicated torsional balance, up to 10 micrometers. Parallelism
of large surfaces, critical in this configuration, is maintained through the
use of inclinometer technology already implemented at Grenoble for the study of
gravitationally bound states of ultracold neutrons, For the dissipative
component of the Casimir force, we discuss detection techniques based upon the
use of hyperfine spectroscopy of ultracold atoms and Rydberg atoms. Although
quite challenging, this triad of experimental efforts, if successful, will give
us a better knowledge of the interplay between quantum and thermal fluctuations
of the electromagnetic field and of the nature of dissipation induced by the
motion of objects in a quantum vacuum.Comment: Contribution to QFEXT'06, appeared in special issue of Journal of
Physics
Exact zero-point interaction energy between cylinders
We calculate the exact Casimir interaction energy between two perfectly
conducting, very long, eccentric cylindrical shells using a mode summation
technique. Several limiting cases of the exact formula for the Casimir energy
corresponding to this configuration are studied both analytically and
numerically. These include concentric cylinders, cylinder-plane, and eccentric
cylinders, for small and large separations between the surfaces. For small
separations we recover the proximity approximation, while for large separations
we find a weak logarithmic decay of the Casimir interaction energy, typical of
cylindrical geometries.Comment: 20 pages, 7 figure