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On a nanophotonic response descriptor

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Anagnostakis E. A.

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2013

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tom Vol.17, No 1-2

91--94

EN

The photonic response exhibited by typical semiconductor nanodevices is modeled through a notionally universal descriptor by virtue of the Green’s function associated with the generic complete, inhomogeneous differential equation. It is derived that the photoresponse evolution is expressible as the sum of saturation-limiting linear nanophotonic behavior and a linear superposition of eigenfunctions of the respective homogeneous Fredholm integral equation.

2

Finite difference method determination of the nano-hetero-interface wave-function engineering of inter-subband LASER functionality

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Anagnostakis E. A.

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tom Vol. 8, No 3

385-392

EN

A novel LASER action nano-hetero-structure of the inter-subband, mid-infrared functionality type is designed on the basis of optically pumped dual resonant tunnelling of conductivity electrons within an appropriately energetically determined scheme of five subbands hosted by two communicating asymmetric, approximately rectangular quantum wells (QWs). The upper LASER action level employed is the second excited subband of the nanostructure's back, wider QW and is provided with electrons via resonant tunnelling from the first excited subband of the nanostructure's front QW populated through remotely ignited optical pumping out of the local fundamental subband. The first excited back QW subband functions as the lower LASER action level, directly delivering the received electrons to the local fundamental subband - via fast vertical longitudinal optical phonon scattering - wherefrom they are being recycled back to the nanostructure's front QW fundamental subband by virtue of a second-reverse sense-resonant tunnelling-mediated normal charge transport mechanism. The handling of the de Broglie wave-function problem evolves into a numerical calculation of a Sturm-Liouville eigensystem solved by means of a finite difference method employing an appropriate tridiagonal coefficient matrix.

3

On negative differential mobility in nanophotonic device functionality

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Anagnostakis E. A.

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2013

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tom Vol. 17, No 3-4

131--137

EN

The negative differential mobility (NDM) of two-dimensional carrier-gas against some proper external regulator allowing gradual controlled modification of the nanointerfacial environment tends to occur as interwoven with the nanophotonic device functionality. In this work, several instances from our two-decade principal research of both experimental observation and conceptual prediction concerning nanophotonics NDM are reconsidered towards outlining a global potential for the appearance of the effect.

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FMR study of magnetic nanoparticles embedded in non-magnetic matrix

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Guskos N. , Anagnostakis E. A. , Guskos A.

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tom Vol. 24, nr 1

26-35

EN

Purpose: The aim of this review is recapitulating the FMR study of low concentration of magnetic nanoparticles in non-magnetic matrices. Design/methodology/approach: Magnetic nanoparticles exhibit a variety of anomalous magnetic properties and they could be used for forming low concentration in different matrices. This way, they are being found to be allowing for effectively novel applications of FMR (ferromagnetic resonance) for easier trustworthy characterisation of a variety of materials. alpha-Fe, Co, Fe3C, gamma- Fe203, Fe3O4 magnetic nanoparticles have been used as low concentration fillers in paraffin, concrete, resin and polymers/copolymers. Findings: For all these matrices, the intensities of the FMR spectra are recorded decreasing with temperature lowering in the high temperature region, whilst the resonance locus is shifted to the direction of lower magnetic field, essentially changing the resonance condition. These parameters of the FMR spectra are seen depending upon kind of a nanoparticle host in such a way that this method could be useful for studying dynamical processes of the matrices. Interestingly enough, a very low concentration of magnetic nanoparticles embedded in the non-magnetic matrix could modify its glass-state emanation or melting transition. Research limitations/implications: Composite systems containing magnetic nanoparticles promise the potential for high-density data storage, biomedical applications, catalysis, and nanotechnology sensor materialisation among other envisaged utilisations. Originality/value: Continue attempting to decipher the mystery and fruitfulness of magnetic nanoparticle distributions.