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Many complex magnetic structures in a high-symmetry lattice can arise from a superposition of well-defined magnetic wave vectors. These "multi-q" structures have garnered much attention because of interesting real-space spin textures such as skyrmions. However, the role multi-q structures play in the topology of electronic bands in momentum space has remained rather elusive. Here we show that the type-I anti-ferromagnetic 1q, 2q and 3q structures in an face-centered cubic sublattice with band inversion, such as NdBi, can induce unconventional surface state pairs inside the band-folding hybridization bulk gap. Our density functional theory calculations match well with the recent experimental observation of unconventional surface states with hole Fermi arc-like features and electron pockets below the Neel temperature. We further show that these multi-q structures have Dirac and Weyl nodes. Our work reveals the special role that band-folding from anti-ferromagnetism and multi-q structures can play in developing new types of surface states., Comment: 31 pages, 11 figures

ZnO:Cu and ZnS thin films were grown by metal-organic chemical vapour deposition (MOCVD) under atmospheric pressure onto glass substrates. The ZnO:Ag films were fabricated from ZnS films by non-vacuum method that consists of simultaneous oxidation and Ag-doping by the close spaced evaporation (CSE) of silver at the temperature of 500–600 °C. Photo-assisted rapid thermal annealing (PARTA) at ambient air during 10–30 s at the temperature of 700–800 °C was used for the ZnO:Cu films. The samples were studied by X-ray diffraction technique (XRD), atomic force microscopy (AFM), and photoluminescence (PL) measurements. The grain size of ZnO:Cu films increased with an increase of Cu concentration. PL spectra of as-deposited ZnO:Cu films depended on Cu concentration and contained the bands typical for the copper. After PARTA at high temperature the emission maximum shifted towards the short-wave region. During the fabrication of ZnO:Ag films the grain growth process was strongly affected by the Ag loading level. The grain size increased with an increase of Ag concentration and ZnO:Ag films with surface roughness of 8 nm were obtained. Observed 385 nm PL peak for these samples can be attributed to the exciton–exciton emission that proves the high quality of the obtained ZnO:Ag films.

We introduce the notion of invariant surfaces for inhomogeneous stochastic differential equations with jumps. The results obtained enable one to determine invariant surfaces for stochastic differential equations of the type indicated.

The characteristics and structural features of a prototype neutron detector based on an СЦ-331 boron-containing molded scintillator manufactured at the Institute for High-Energy Physics are described. Owing to the use of this scintillator, the neutron detector is capable of operating at high counting rates with a relatively low level of background events. The detectors developed are applicable to neutron flux measurements in extensive air showers.

In the experiments at the SPHINX facility in 70 GeV proton beam of the IHEP accelerator the coherent diffractive production reactions on carbon nucleip+C→ [∑(1385)0K++C andp+C→[Σ0K+]+C were investigated. The evidences for new baryon states were obtained in the study of hyperon-kaon effective mass spectra in these two reactions:X (2050) with massM=(2052±6) MeV and width Γ=(35−35+22) MeV inM[∑(1385)0K+] andX(2000) withM=1999±6 MeV and Γ=91±17 MeV inM[Σ0K+]. The unusual features of these massive states (small enough decay widths, anomalously large branching ratios for decays with strange particles emission) make them very serious candidates for cryptoexotic pentaquark baryons with hidden strangeness.

In the experiments at the SPHINX facility in the 70 GeV proton beam of the IHEP accelerator the diffractive production reactionsp+N→[Σ(1385)0K+] +N andp+N→[Σ(1385)0K+]+N+ (neutral particles) were studied. In the effective mass spectra of the [Σ(1385)0K+] system in these processes there were no signals from the anomalously narrow baryon stateNϕ (1960) which had been observed earlier in the measurement at the BIS-2 setup.

The reactions of baryon diffractive productionp+N→(pK + K −)+N, p+N→(pϕ)+N, p+N→[Λ(1520)K +]+N p+N→[Σ(1385) o K +]+N in the 70 GeV proton beam were studied. Very sensitive upper limits for the production cross sections of heavy narrow cryptoexotic baryon resonances with hidden strangeness were obtained.

On the basis of the finite element method (FEM) the authors devised an effective apparatus of numerical investigation of processes of failure of axisymmetric complexly shaped bodies under plane strain, induced by propagation of initial cracks in them. This apparatus was worked out on the basis of the use of special finite elements approximating the existence of a crack from the condition that the stresses normal and tangential to its path are equal to zero. The article suggests new modifications of the method of separate calculation of stress intensity factors and of an algorithm for solving problems of linear fracture mechanics when the path of crack propagation is not known. The reliability of the results obtained with the application of the new method and realizing its complex of programs was confirmed by the solution of control problems. An illustration of the possibilities of the method and of the complex is the calculation of the load bearing capacity of a permanent joint of a cylindrical glass shell with a metallic end cap.

A formula that connects the eigenvalues of the energy operator of a system of interacting fields with the S matrix generated by the operator of the interaction energy is derived.

1. The shape of the thermal damage resistance diagrams depends mainly upon the behavioral characteristics of the materials under load and are characterized by the degree of brittleness Χ. 2. After thermal shock impairment of samples from material which in the original state is brittle (Χ=1) nonelastic strain is observed and the degree of brittleness becomes less than unity. Along with this, the fracture properties change as well as the resistance to subsequent mechanical and thermal loads.

The vibrational and hyperfine structure of the infrared absorption spectra of KCl and KBr crystals doped with the molecular monovalent anions of nitrogen dioxide and nitrogen trioxide and additionally doped or not doped with divalent cations of calcium and barium is analyzed at a temperature of 4.2 K in this paper. The penetration of the ions into the crystal lattices and their complexing behavior with the halides are determined. The isotopic structure of the infrared spectra is also analyzed for nitrogen dioxide and trioxide anions comprised of nitrogen 14/oxygen 16, nitrogen 15/oxygen 16, nitrogen 14/oxygen 18, and nitrogen 14/oxygen 16/oxygen 18 isotope compositions.

In this study the authors calculate the masses of the charge leptons of different generations (the electron, muon, and tau-lepton) with the framework of the unified theory of weak and electromagnetic interactions. They assume that the bare masses of the charge leptons are nonzero and the bare masses of the neutral leptons (i.e., the neutrinos) are equal to zero. The total (experimental) mass of a charge lepton is due to its interaction with the vacua of the electromagnetic, W-boson, and Z-boson fields. The contribution of these vacua to the mass of the charged lepton is equivalent to the contribution from the vacuum of a certain equivalent fictitious field, whose quanta they will call fictitions. The fictition is as an auxiliary fictitious particle, which is introduced to realize the calculational apparatus that they introduce. They assume that the fictition is a pseudoscalar particle with a mass M/sub p/ = ..mu..hc and with a zero spin and a zero electric charge

An attempt is made in this paper to construct a scalar theory of gravitation which is based on the main postulates of the general theory of relativity (GTR), i.e., on the principle of the equivalence of inertial and gravitational mass and on the principle of general covariance of the theory.

1. Diamond grinding of fine-grained compact ceramic materials increase their strength considerably. 2. The parameters of diamond grinding do not have a substantial effect on the strength of the material. 3. An effect of the parameters of the regimes of diamond grinding and of the grain size of the diamond wheel on the resistance of the material to thermal loading was not found at all levels of this loading but only at those below the critical values for the given material.

This study will attempt to construct a unified theory of weak, strong, electromagnetic, and gravitational interactions, based on a generalization of Weinberg-Salam theory [1] and a theory proposed previously by the present author [2, 3].