Magnetic force microscopy of epitaxial Fe2CoAl and Co2FeAl Heusler alloy films and microstructures

Research supported by RFBR grant 17-57-45024 IND-a

Nonlinear Optical Dynamics and High Reflectance of a Monolayer of Three-Level Quantum Emitters with a Doublet in the Excited State

Abstract: We study theoretically the nonlinear optical response of a monolayer of regularly arranged three-level identical quantum emitters with a doublet in the excited state to the action of a monochromatic electromagnetic field quasi-resonant to optical transitions in the emitter. The total retarded dipole–dipole interaction of the emitters is accounted for in the mean-field approximation. This interaction plays the role of a positive feedback, which (in combination with the immanent nonlinearity of emitters themselves) leads to multistability of the monolayer response. The stability of different response branches is analyzed using the Lyapunov exponents method. It is found that the instability type depends on the doublet splitting and changes from self-oscillations to chaos upon increasing the splitting. Another important property of the monolayer is its high (almost 100%) reflectance in a certain frequency range; i.e., within this range, the monolayer operates as a perfect nanometer mirror; moreover, reflection can be switched to transmission changing slightly the incident field amplitude (bistability). The possibility of application of the above mentioned monolayer optical properties in nanophotonics is discussed

LINGUO-STYLISTIC MEANS OF CREATING THE IMAGE OF THE «NATURAL MAN» IN THE NOVEL THE LIFE OF PI BY Y. MARTEL

This article is devoted to the linguo-stylistic analysis of the image of Pisin Molitor Patel as a central component of the artwork in the context of plot development. Purpose. The identification and analysis of the means of creating the image of the «natural man» in the novel «The Life of Pi» by Y. Martel. The work uses such research methods as the analysis of theoretical literature on the problem of research, the method of continuous sampling, the method of linguostylistic analysis, corpus analysis of text, comparative-comparative analysis. Results: The results of the study showed that with the help of a set of explicit linguistic and stylistic means Y. Martel creates an image of a “natural man” who relies on human reason in everything and in a difficult situation is guided by common sense rather than emotions and feelings and proceeds to fulfil the primary tasks necessary for survival. In addition, the linguistic and stylistic means of indirect characterisation identified in the thoughts, direct and inner speech serve to indicate the leading role of common sense and intellect in the construction of the protagonist’s image as a “natural man”

Multiloop Superstring Amplitudes from Non-Minimal Pure Spinor Formalism

Using the non-minimal version of the pure spinor formalism, manifestly super-Poincare covariant superstring scattering amplitudes can be computed as in topological string theory without the need of picture-changing operators. The only subtlety comes from regularizing the functional integral over the pure spinor ghosts. In this paper, it is shown how to regularize this functional integral in a BRST-invariant manner, allowing the computation of arbitrary multiloop amplitudes. The regularization method simplifies for scattering amplitudes which contribute to ten-dimensional F-terms, i.e. terms in the ten-dimensional superspace action which do not involve integration over the maximum number of $\theta$'s.Comment: 23 pages harvmac, added acknowledgemen

New stratigraphic data on the quaternary sediments in the Peschanaya River Valley, Northwestern Altai

© 2017 Siberian Branch of the Russian Academy of Sciences. This paper presents new data on the structure and the lithological, pedological, paleontological, and paleomagnetic features of the Middle and Upper Quaternary sediments in the Peschanaya River valley, the foothills of northwestern Altai. Those horizons contain a loess-soil sequence and sediments relating to two Middle Pleistocene interglacials. On the basis of palynological characteristics of one of the Middle Pleistocene interglacials, the succession of fl oras during the respective stages is reconstructed. The Middle Pleistocene interglacial fl oras of Western Siberia are compared with that reconstructed on the basis of the Karama site, evidencing marked differences. The fl ora around Karama included broad-leaved taxa, which were absent during the Middle Pleistocene interglacials of Western Siberia, when apart from modern arboreal taxa, only cold-resistant broad-leaved ones were present (Tilia, Corylus, Ulmus, and Juglans). The Karama fl ora resembles the last Western Siberian thermophilic fl ora-Barnaul, which existed during the long climatic warming of the Early Pleistocene, corresponding to the Tiglian in northwestern Europe (2.23-1.59 Ma BP). Since the beginning of the Middle Pleistocene, interglacial fl oras of Western Siberia have resembled modern ones. In terms of phytocenotic and palaeoclimatic features, Middle Pleistocene interglacial environments of Western Siberia display a sharp contrast with those of Barnaul and Karama

Nonlinear optical dynamics of a 2D semiconductor quantum dot super-crystal: emerging multistability, self-oscillations and chaos

We conduct a theoretical study of the nonlinear optical dynamics of a 2D super-crystal comprising regularly spaced identical semiconductor quantum dots (SQDs), subjected to a resonant continuous wave excitation. A single SQD is considered as three-level ladder-like systems involving the ground, one-exciton and bi-exction states. We show that the super-crystal reveals a rich nonlinear dynamics, exhibiting multistability, self-oscillations and chaos. The behaviour is driven by the retarded SQD-SQD interactions and bi-exciton binding energy

Gaudin Model, Bethe Ansatz and Critical Level

We propose a new method of diagonalization of hamiltonians of the Gaudin model associated to an arbitrary simple Lie algebra, which is based on Wakimoto modules over affine algebras at the critical level. We construct eigenvectors of these hamiltonians by restricting certain invariant functionals on tensor products of Wakimoto modules. In conformal field theory language, the eigenvectors are given by certain bosonic correlation functions. Analogues of Bethe ansatz equations naturally appear as Kac-Kazhdan type equations on the existence of certain singular vectors in Wakimoto modules. We use this construction to expalain a connection between Gaudin's model and correlation functions of WZNW models.Comment: 40 pages, postscript-file (references added and corrected

Optimization of the drainage system of overburden dumps using geofiltration modeling

The article describes the assessment of the predicted water flows at the site of the projected rock dumps, which was carried out using geofiltration modeling. When developing the model, we used actual data on capacities, filtration coefficients and water capacity, roof and sole marks of the selected aquifers, precipitation infiltration, as well as the projected dumps are located on the slope surfac