3,469 research outputs found
Influence of non-stationary field of magnetospheric convection on the D-region
Perturbations of F region electron density caused by the extension of magnetospheric convection electric field to middle latitudes are already well known. For the D region of the first observations are believed to be reported by Eliseyev, Kashpar and Nikitin (1988). On several occasions, following the southward turning of the Bz-component of interplanetary magnetic field (IMF) small disturbances of the D region electron density were detected at night by steep-incidence VLF sounding, which may be attributed to the influence of the penetrated convection electric field (CEF). Some evidence is given of a local time dependence of the CEF effect in the D region and a rather good correlation is demonstrated at the initial stage of disturbance between high latitude magnetic field variations and simultaneous perturbation of the midlatitude ionospheric reflection height
Edge and waveguide THz surface plasmon modes in graphene micro-ribbons
Surface plasmon modes supported by graphene ribbon waveguides are studied and
classified. The properties of both modes with the field concentration within
the ribbon area (waveguiding modes) and on the edges (edge modes) are
discussed. The waveguide and edge modes are shown to be separated from each
other by a gap in wavenumbers. The even-parity hybridized edge mode results to
be the fundamental electromagnetic mode of the ribbon, possessing also the
lowest losses. All the plasmonic modes in the ribbons have an optimum
frequency, at which the absorption losses are minimum, due to competition
between the plasmon confinement and the frequency dependence of absorption in
graphene.Comment: 4 pages, 4 figure
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