4,572 research outputs found
Uniqueness of a 3-D coefficient inverse scattering problem without the phase information
We use a new method to prove uniqueness theorem for a coefficient inverse
scattering problem without the phase information for the 3-D Helmholtz
equation. We consider the case when only the modulus of the scattered wave
field is measured and the phase is not measured. The spatially distributed
refractive index is the subject of the interest in this problem. Applications
of this problem are in imaging of nanostructures and biological cells
Time-dependent angularly averaged inverse transport
This paper concerns the reconstruction of the absorption and scattering
parameters in a time-dependent linear transport equation from knowledge of
angularly averaged measurements performed at the boundary of a domain of
interest. We show that the absorption coefficient and the spatial component of
the scattering coefficient are uniquely determined by such measurements. We
obtain stability results on the reconstruction of the absorption and scattering
parameters with respect to the measured albedo operator. The stability results
are obtained by a precise decomposition of the measurements into components
with different singular behavior in the time domain
Electron Bloch Oscillations and Electromagnetic Transparency of Semiconductor Superlattices in Multi-Frequency Electric Fields
We examine phenomenon of electromagnetic transparency in semiconductor
superlattices (having various miniband dispersion laws) in the presence of
multi-frequency periodic and non-periodic electric fields. Effects of induced
transparency and spontaneous generation of static fields are discussed. We paid
a special attention on a self-induced electromagnetic transparency and its
correlation to dynamic electron localization. Processes and mechanisms of the
transparency formation, collapse, and stabilization in the presence of external
fields are studied. In particular, we present the numerical results of the time
evolution of the superlattice current in an external biharmonic field showing
main channels of transparency collapse and its partial stabilization in the
case of low electron density superlattices
Prediction for new magnetoelectric fluorides
We use symmetry considerations in order to predict new magnetoelectric
fluorides. In addition to these magnetoelectric properties, we discuss among
these fluorides the ones susceptible to present multiferroic properties. We
emphasize that several materials present ferromagnetic properties. This
ferromagnetism should enhance the interplay between magnetic and dielectric
properties in these materials.Comment: 12 pages, 4 figures, To appear in Journal of Physics: Condensed
Matte
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