Long-distance propagation of a surface plasmon on the surface of a ferromagnetic metal.

A method for the reduction of the propagation loss of surface plasmons was proposed and experimentally demonstrated. A plasmonic structure, which contains a metal and two dielectric layers of different refractive indexes, is proposed in order to optimize the optical confinement and to reduce the propagation loss of the surface plasmons. Long-distance propagation of a surface plasmon on the surface of a ferromagnetic metal was demonstrated. A low propagation loss of 0.17 dB/µm for a surface plasmon in a Fe/MgO/AlGaAs plasmonic structure was achieved.

Magnetization-dependent loss in an (Al,Ga)As optical waveguide with an embedded Fe micromagnet.

The dependence of waveguiding loss on the magnetization of a Fe micromagnet embedded into the (Al,Ga)As optical waveguide was examined as a possible readout method for the spin-photon memory. The optical detection of the magnetization direction of a Fe micromagnet was demonstrated for the micromagnet sizes of 3 microm x 4 microm and 3 microm x 8 microm with signal-to-noise ratios of 4.8 and 6 dB, respectively. In the case of smaller sizes, the use of spin injection from the micromagnet into a semiconductor optical amplifier was proposed for the optical detection of the magnetization.

Stabilization of AIMP1/p43 and EMAP II recombinant proteins in the complexes with polysaccharide dextran-70.

BACKGROUND: Protein-based pharmaceuticals are among the fastest growing categories of therapeutic agents in the clinic and as commercial products, and typically target high-impact areas such as various cancers, autoimmune diseases and metabolic disorders. The aim of our work was to explore the possibility of reducing the level of aggregation and improve the stability of the recombinant proteins AIMP1/p43 (aminoacyl-tRNA synthetase complex component of the higher eukaryotes) and antitumor cytokine EMAP II (proteolytic cleavage product of AIMP1/p43) in combination with dextran-70 polysaccharide for structural-functional research and development of new sustainable biomedical products. METHODS: We studied interaction strength between these recombinant proteins with polymer by fluorescence spectroscopy and molecular docking. RESULTS: During experimental studies, optimal concentration ratio of AIMP1/p43 and EMAP II recombinant proteins with dextran-70 in which proteins bind to ligand and form complex was established. As a result of molecular docking investigations, spatial structure of the AIMP1/p43-dextran-70 and EMAP II-dextran-70 complexes was obtained and their binding energy was evaluation. CONCLUSIONS: The effect of temperature increase on the stability of these two complexes was determined by fluorescence spectroscopy method. It was found that dextran-70 specifically connects with recombinant proteins. Binding stoichiometry of dextran-70 with protein is about 1:1, which confirms the formation of a specific complex.

Origin of the anomalous magnetic circular dichroism spectral shape in ferromagnetic Ga(1-x)MnxAs: impurity bands inside the band gap.

The electronic structure of a prototype dilute magnetic semiconductor (DMS), Ga(1-x)MnxAs, is studied by magnetic circular dichroism (MCD) spectroscopy. We prove that the optical transitions originated from impurity bands cause the strong positive MCD background. The MCD signal due to the E0 transition from the valence band to the conduction band is negative indicating that the p-d exchange interactions between the p carriers and d spin is antiferromagnetic. The negative E0 MCD signal also indicates that the hole doping of the valence band is not so large as previously assumed. The impurity bands seem to play important roles for the ferromagnetism of Ga(1-x)MnxAs.

Room-temperature ferromagnetism in a II-VI diluted magnetic semiconductor Zn(1-x)Cr(x)Te.

The magnetic and magneto-optical properties of a Cr-doped II-VI semiconductor ZnTe were investigated. Magnetic circular dichroism measurements showed a strong interaction between the sp carriers and localized d spins, indicating that Zn(1-x)Cr(x)Te is a diluted magnetic semiconductor. The Curie temperature of the film with x=0.20 was estimated to be 300+/-10 K, which is the highest value ever reported for a diluted magnetic semiconductor in which sp-d interactions were confirmed. In spite of its high Curie temperature, Zn(1-x)Cr(x)Te film shows semiconducting electrical transport properties.