Engineering of Low-Loss Metal for Nanoplasmonic and Metamaterials Applications

We have shown that alloying a noble metal (gold) with another metal (cadmium), which can contribute two electrons per atom to a free electron gas, can significantly improve the metals optical properties in certain wavelength ranges and make them worse in the other parts of the spectrum. In particular, in the gold-cadmium alloy we have demonstrated a significant expansion of the spectral range of metallic reflectance to shorter wavelengths. The experimental results and the predictions of the first principles theory demonstrate an opportunity for the improvement and optimization of low-loss metals for nanoplasmonic and metamaterials applications.Comment: 14 Pages, 4 figure

Cyclotron resonance of extremely conductive 2D holes in high Ge content strained heterostructures

Cyclotron resonance has been observed in steady and pulsed magnetic fields from high conductivity holes in Ge quantum wells. The resonance positions, splittings and linewidths are compared to calculations of the hole Landau levels

Excitonic effects in solids described by time-dependent density functional theory

Starting from the many-body Bethe-Salpeter equation we derive an exchange-correlation kernel $f_{xc}$ that reproduces excitonic effects in bulk materials within time-dependent density functional theory. The resulting $f_{xc}$ accounts for both self-energy corrections and the electron-hole interaction. It is {\em static}, {\em non-local} and has a long-range Coulomb tail. Taking the example of bulk silicon, we show that the $- \alpha / q^2$ divergency is crucial and can, in the case of continuum excitons, even be sufficient for reproducing the excitonic effects and yielding excellent agreement between the calculated and the experimental absorption spectrum.Comment: 6 pages, 1 figur

Refitting of combined inner detector and muon spectrometer tracks from Monte Carlo samples by using the Kalman fitter and the STEP algorithm in the ATLAS experiment

In this paper we refit combined muon tracks using the Kalman fitter and the simultaneous track and error propagation (STEP) algorithm of the ATLAS tracking software. The muon tracks are simulated by GEANT4 in the full detector description, reconstructed by MUID, and refitted by the Kalman fitter in the ATLAS TrackingGeometry. The relative transverse momentum resolution of the refitted tracks is compared to the resolution of the refits done by the global chi-square track fitter, along with the resolution found by the MUID and STACO muon combination algorithms. Reconstructed invariant masses are compared in a similar way

Syntectonic mobility of supergene nickel ores of New Caledonia (Southwest Pacific). Evidence from faulted regolith and garnierite veins.

International audienceSupergene nickel deposits of New Caledonia that have been formed in the Neogene by weathering of obducted ultramafic rocks are tightly controlled by fracture development. The relationship of tropical weathering and tectonic structures, faults and tension gashes, have been investigated in order to determine whether fractures have play a passive role only, as previously thought; or alternatively, if brittle tectonics was acting together with alteration. From the observation of time-relationship, textures, and mineralogy of various fracture fills and fault gouges, it may be unambiguously established that active faulting has play a prominent role not only in facilitating drainage and providing room for synkinematic crystallisation of supergene nickel silicate, but also in mobilising already formed sparse nickel ore, giving birth to the very high grade ore nicknamed "green gold"

Nomenclatural standards and genetic passports of potato cultivars bred by the Omsk Agrarian Research Center

In accordance with the International Code of Nomenclature for Cultivated Plants, five nomenclature standards were prepared for five potato сultivars* bred in the Omsk Agrarian Research Center: ‘Alena’, ‘Bylina Sibiri’, ‘Večernij Omsk’, ‘Triumf’, ‘Hozâûška’. Genetic passport of these five cultivars were carried out according to the new integrated strategy developed at VIR. According to the strategy, the plant material donated by the author of the cultivars to the VIR Herbarium was used for molecular genotyping. Genetic passports included data of allelic composition of eight chromosome specific microsatellite loci, markers of different types of organelle DNA, as well as data about diagnostic fragments of 15 markers of 11 R-genes conferring resistance to the most dangerous diseases and pests of potato: late blight, nematodes, potato X and Y viruses. Data from the developed genetic passports of five Omsk cultivars were compared to the results of genotyping of samples of the same cultivars obtained from different sources. Based on the analysis of pedigrees and genetic passports of these five cultivars we established the origin of their resistance to harmful organisms

Emission spectra of terahertz quantum cascade laser

We calculated energy levels, wave functions, and energies of radiative transitions in terahertz quantum cascade lasers based on GaAs/Al0.15Ga0.85As heterostructures. Current-voltage characteristics and current dependences of laser radiation intensity were measured, and the maximum operating temperatures reaching 85 K were determined. Radiation spectra of quantum cascade lasers were measured for different temperatures, and the effect of intensity “pumping” from lowfrequency modes to high-frequency modes was found to happen in the case of an increase in the current and time delay of the signal capture, which is explained by heating of the sample during a pulse of the current. Application of the lasers for registration of impurity photoconductivity signals in semiconductor heterostructures was demonstrated

Second harmonic generation in SiC polytypes

LMTO calculations are presented for the frequency dependent second harmonic generation (SHG) in the polytypes 2H, 4H, 6H, 15R and 3C of SiC. All independent tensor components are calculated. The spectral features and the ratios of the 333 to 311 tensorial components are studied as a function of the degree of hexagonality. The relationship to the linear optical response and the underlying band structure are investigated. SHG is suggested to be a sensitive tool for investigating the near band edge interband excitations.Comment: 12 pages, 10 figure

Nomenclatural standards, voucher specimens and genetic passports of potato cultivars created in the Siberian and Ural breeding centers

The present paper discusses methodological approaches to the creation of nomenclatural standards and genetic passports for Russian cultivars, currently being developed at the N.I. Vavilov Institute of Plant Genetic Resources (VIR) in collaboration with different breeding research centers. Plant material of potato cultivars bred in the Siberian Research Institute of Plant Cultivation and Breeding was collected by the cultivar creator A.D. Safonova in the experimental field of this institute and transferred to the VIR herbarium for preparation of their nomenclatural standards. Plant shoots and tubers of potato cultivars bred in other Siberian research centers in collaboration with the A.G. Lorkh All-Russian Research Institute of Potato Farming (VNIIKH) was collected by the representative of this institute in the experimental field of VNIIKH. As a result of joint research, nomenclatural standards were accomplished for 11 cultivars, namely ‘Аntonina’, ‘Zlatka’, ‘Lina’, ‘Lûbava’, ‘Nakra’, ‘Pamâti Rogačeva’, ‘Sarovskij’, ‘Safo’, ‘Solnečnyj’, ‘Tuleevskij’, ‘Ûna’** bred in five different Siberian breeding institutes including cultivars developed in collaboration with VNIIKH. Nomenclatural standards were prepared according to the ‘International Code of Nomenclature for Cultivated Plants’. DNA samples isolated from nomenclatural standards were used for preparation of genetic passports of these 11 cultivars. These genetic passports include information of the polymorphism of eight chromosome-specific microsatellites, data on the markers of 11 R-genes conferring resistance to various harmful organisms, as well as the information about cytoplasm types. Voucher specimens of additional three Siberian cultivars ‘Kemerovčanin’, ‘Kuznečanka’, ‘Tanaj’ and five Ural cultivars ‘Аlâska’, ‘Bravo’, ‘Irbitskij’, ‘Lûks’, ‘Terra’ from the Ural Research Institute for Agriculture were also registered in the VIR herbarium collection. For these eight cultivars, the genetic passports were not issued, but the results of SSR genotyping and molecular screening of voucher specimens performed with the same set of the DNA markers are presented in this report. A similar set of DNA markers was used for genotyping cultivar accessions from the in vitro and field collections of various institutes as well as cultivar specimens from eco-geographical tests performed within the framework of the Comprehensive Research Plan of the subprogram “Development of potato breeding and seed production in the Russian Federation”. The comparison of cultivar genetic passport data with genotyping results of specimens having the same name, but obtained from different sources made it possible to verify this plant material