Mesoscopic variations of local density of states in disordered superconductors

We explore correlations of inhomogeneous local density of states (LDoS) for impure superconductors with different symmetries of the order parameter (s-wave and d-wave) and different types of scatterers (elastic and magnetic impurities). It turns out that the LDoS correlation function of superconductor always slowly decreases with distance up to the phase-breaking length $l_{\phi}$ and its long-range spatial behavior is determined only by the dimensionality, as in normal metals. On the other hand, the energy dependence of this correlation function is sensitive to symmetry of the order parameter and nature of scatterers. Only in the simplest case of s-wave superconductor with elastic scatterers the inhomogeneous LDoS is directly connected to the corresponding characteristics of normal metal.Comment: 16 pages, 5 figures, accepted to Phys. Rev.

Predicted reconstruction of the profile distribution of minerals according to the content of the stable component in the crust light solonetz of dry-steppe zone in the south of Russia

On the basis of detailed, conjugated, qualitative and quantitative analysis of clay and clastogenic minerals of the crust solonetz of the Volga region, the profile composition of minerals is calculated according to the content of a stable component. At the same time, the initial mineralogical homogeneity of the soil profile, determined by the method of a stable component – the content of К-feldspar in the profile, was adapted. Soil density indicators were not involved in the calculations. Profile calculations of minerals were carried out at the level of losses and increases of their percentage in genetic horizons relative to the rock, expressed in kg/100 kg of rock. Design values for clay minerals – negative in suprasolonetz and positive – in solonetz horizons. For clastogenic minerals, negative design values are set in suprasolonetz, with a maximum decrease in solonetz gori-umbrellas, and positive in accumulative-carbonate horizons. The calculated values of minerals and masses of the silicate part allowed establishing the deep development of the soil profile, which was revealed by negative values of the mass of clastogenic minerals and an excess mass of clay minerals in the illuvial part of the profile with respect to potassium feldspar. The accumulation of illite in the surface horizons is explained both by the illitization process and by the significant physical crushing of mica minerals of large fractions to the size of silty particles. The lithological heterogeneity of the profile affects the distortion of the calculation results. Calculated model of substances is formed in solonetz profile by real distribution of mineralogical components of eluvial-illuviation process

Mineralogical comparative analysis of the clay fraction of solonetz and chestnut soil without apparent microrelief in the north-western part of the Caspian lowland

A comparative analysis of the mineralogical composition of the clay fraction (< 1 μm) of chestnut soil and solonetz has been performed in the article. Soils were studied in the oldest part of the Caspian lowland in north-west where the microrelief is not quite apparent (microdepressions no more than 5–10 cm depth), but with a contrast soil cover. The content of silt fraction in chestnut soil varies from 25.6 to 33.9%, in the solonetz – from 11.7 to 51.6%. In all horizons of the compared soils, except for the upper surface horizons (SEL, AU1), mixed-layered minerals dominate (39–52% in the fraction) over illite (27–37% in the fraction). In the surface horizons illite (48%) dominates over mixed-layer minerals (35%). The compared soils have some similarities in their crystal-chemical state: the imperfection of the kaolinite structure and the superdispersed state of the mixed-layer phase in the upper horizons, as well as the appearance of individual smectite and chlorite packets in the mixed-layer phase in the lower horizons (BC, C). The degree of perfection of the kaolinite structure both in the solonetz and in the meadow-chestnut soil increases towards the bottom of the profiles. The obtained data allow suggesting that in the meadow-chestnut soil the clay phase retained traces of the solonetzic stage of soil formation

Temperature dependence of the collective mode and its influence on the band splitting in bilayer cuprates

The recently observed bilayer splitting in high-T$_c$ cuprates is analyzed within a model where the charge carriers are coupled to a phenomenological bosonic spectrum which interpolates between the marginal Fermi liquid structure and collective mode type behavior as a function of temperature. We argue that the origin of the collective mode is probably associated with dynamic incommensurate charge density waves. Moreover it is shown that the resulting temperature dependence of the self-energy $\Sigma$ is in good agreement with $\Sigma$ as extracted from angle-resolved photoemission data.Comment: 6 pages, 4 figures, accepted for PR

DIFFERENTIATION AND BALANCE OF MINERALS DURING TRANSFORMATION OF THE OPEN SURFACE OF ARABLE SOILS UNDER THE IMPACT OF RAIN

During the model experiment the changes in the mineralogical composition of the open surface of arable soil (leached chernozem, gray forest soil, sod-podzolic soil) under the impact of raindrops under fallow conditions were studied. At the end of the experiment a mineralogical analysis of individual particle size fractions < 1, 1–5, 5–10 and > 10 μm from microcrusts formed on open surfaces and a soil substrate not exposed to the effects of precipitation was conducted. The study found that during the exposure there was redistribution and changes in the proportional ratios of the contents of different particle size fractions and associated clay and clastogenic minerals. During the experiment the most significant changes due to their composition occurred in the sample of sod-podzolic soil and leached chernozem. The content of clay minerals in exposed samples decreased the most. The redistribution of clastogenic minerals from the upper open layer, mostly from fine silt and to a lesser extent from the middle silty fraction, was accompanied by a relative accumulation of the fraction > 10 μm. The redistribution of granulometric fractions was accompanied by a relative accumulation of quartz, orthoclases and a decrease in the content of chlorite and biotide in them. Such a distribution is determined by their resistance to weathering. Balance calculations allowed establishing that the total losses of clay and clastogenic minerals from the upper open surface of the monoliths in comparison with the initial soil substrate were more than 4 kg / 100 kg of monolith for gray forest soil, 16 kg / 100 kg of monolith for leached chernozem and 46 kg / 100 kg of monolith for sod-podzolic soil

Two-gap model for underdoped cuprate superconductors

Various properties of underdoped superconducting cuprates, including the momentum-dependent pseudogap opening, indicate a behavior which is neither BCS nor Bose-Einstein condensation (BEC) like. To explain this issue we introduce a two-gap model. This model assumes an anisotropic pairing interaction among two kinds of fermions with small and large Fermi velocities representing the quasiparticles near the M and the nodal points of the Fermi surface respectively. We find that a gap forms near the M points resulting into incoherent pairing due to strong fluctuations. Instead the pairing near the nodal points sets in with phase coherence at lower temperature. By tuning the momentum-dependent interaction, the model allows for a continuous evolution from a pure BCS pairing (in the overdoped and optimally doped regime) to a mixed boson-fermion picture (in the strongly underdoped regime).Comment: 5 pages, 1 enclosed figure. For further information see http://htcs.or

Non-silicate iron in mineral-associated organic matter of agro-chernozems located on different positions on the slope

Data on total non-silicate iron (Fed) content in mineral-associated organic matter (MAOM) of agro-chernozems of different localization on the slope are presented. The distribution of total non-silicate iron in soil profile follows that of organic carbon (OC): the maximum values are confined to the surface horizons, and decrease down the profile. It has been revealed that the change in the content of non-silicate iron in the MAOM of the clay fraction in arable horizons of eroded agro-chernozems is a result of erosion processes, including their intensity, which also depends, among other things, on the slope steepness. A lower slope steepness (4°) contributes to an increase in the organic carbon loading on iron oxides, resulting in an increased in iron desorption capacity, while a higher slope steepness (6°) results in lower iron desorption capacity. The OC/Fed molar ratio is suggested as an additional indicator of the degree of soil erosion. In clay fractions, of both their position in the soil profile and their position on the slope, the predominant mechanism of organic matter stabilization was the formation of organic-iron complexes (OC/Fed > 10). In the Residue fraction of humus horizons, non-silicate iron seems to be presented mainly as iron carbonates (FeCO3), while the proportion of microaggregates (stable under the sonication), where OM is mainly humin, is relatively low against the background of the absolute dominance of primary minerals in this fraction (weight %). Most of the non-silicate iron of mineralassociated OM extracted by dithionite-citrate-hydrocarbonate is localized in the clay fraction – 2/3 or more

Morphology, mineralogical composition and genesis of vertisols in liman Bolshoi (Volgograd region)

The morphological structure of the profiles of two vertisols on microelevations of the gilgai complex of the Bolshoi liman (Svetloyarsk district of the Volgograd region) was studied. Despite the same microrelief position and equal relative heights of microelevations, morphological differences in the profiles at the subtype level were revealed. In one of the profiles, due to the higher humidity, the signs of vertisol genesis were less pronounced. Whereas in the second, more pronounced signs of vertic processes were described – slickensides with 15–30 cm length, smaller slickensides up to 10 cm, wedge-shaped aggregates. The proportion of the clay fraction in the mixed horizons, obtained by the Gorbunov method, was 45– 52%. Analysis of the qualitative mineralogical composition of the clay (<1μm) fractions showed that the smectite phase is represented mainly by disordered and mixed-layered smectite-illite formations. Individual illite belongs to the biotite variety according to the filling of the octahedral layer. Analysis of the ratio of the main mineral phases showed the predominance of illite (53–87%) in all soil samples. In the first pit an increase in the proportion of the smectite component with depth (from 1 to 35%) is noted. In the second pit, there are no regularities in the distribution of mineral phases (fluctuations within 24–37%), which may be associated with the involvement of chocolate clays layers in the profile during soil formation. Mineralogical analysis of chocolate clays (parent rocks) showed their high heterogeneity depending on the depth of the studied layer. No correlation was found between the severity of the signs of vertic processes and the proportion of the swelling component. Illustration of the stages of the formation of the soil cover on the investigated plot of the liman is given. The main reasons that led to the formation of different soils on microelevations are the unevenness of the “squeezing out” of soil blocks upward in the process of microrelief formation in combination with local erosion

Micromorphological features of soils of semidesertic solonetzic complexes under different herbaceous communities with the participation of fodder plant Kochia prostrata (Caspian lowland)

The aim of the study was to research the relationship of chemical and micromorphological properties of soils with the growth of Kochia prostrata. The objects of study were the soils on natural pastures of the North-Western part of the Caspian lowland. It was laid 4 soil pits (soils – light solonetz, solonetzic chestnut) with the maximum penetration depth of the main mass of roots of the studied plants. K. prostratais a very plastic forage species that can grow on soils with a wide range of morphological properties, different salt content and their chemical composition. It is revealed that on the background of almost the same content of humus and high content of exchangeable magnesium micromorphological features represent the different degree of manifestation of primary pedogenic processes – humus accumulation, leaching of soluble salts, gypsum accumulation, carbonate enrichment, solonetzization. Despite the different content of exchangeable sodium, in all soils there are fresh clay or humus-clay illuvial coatings, indicating the manifestation of the modern eluvial-illuvial redistribution of fine matter (lessivage or illimerization)