35,939 research outputs found
Light dynamics in glass-vanadium dioxide nanocomposite waveguides with thermal nonlinearity
We address the propagation of laser beams in Si02-VO2 nanocomposite
waveguides with thermo-optical nonlinearity. We show that the large
modifications of the absorption coefficient as well as notable changes of
refractive index of VO2 nanoparticles embedded into the SiO2 host media that
accompany the semiconductor-to-metal phase transition may lead to optical
limiting in the near-infrared wave range.Comment: 13 pages, 3 figures, to appear in Optics Letter
molecular ions can exist in strong magnetic fields
Using the variational method it is shown that for magnetic fields G there can exist a molecular ion .Comment: LaTeX, 7 pp, 1 table, 4 figures. Title modified. Consideration of the
longitudinal size of the system was adde
Three-body Casimir effects and non-monotonic forces
Casimir interactions are not pair-wise additive. This property leads to
collective effects that we study for a pair of objects near a conducting wall.
We employ a scattering approach to compute the interaction in terms of
fluctuating multipoles. The wall can lead to a non-monotonic force between the
objects. For two atoms with anisotropic electric and magnetic dipole
polarizabilities we demonstrate that this non-monotonic effect results from a
competition between two- and three body interactions. By including higher order
multipoles we obtain the force between two macroscopic metallic spheres for a
wide range of sphere separations and distances to the wall.Comment: 4 pages, 4 figure
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