J Phys Condens Matter
July 2021
To describe kinetic phenomena in disordered conductors, various acts of scattering of electrons can be often considered as independent, that is captured by the Boltzmann equation. However, in some regimes, especially, in a magnetic field, it becomes necessary to take into account the correlations between different scattering events of electrons on defects at different times in the past. Such memory effects can have a profound impact on the resistivity of 2D semiconductor systems, resulting in giant negative magnetoresistance and microwave-induced resistance oscillations phenomena.
View Article and Find Full Text PDFThe topological Hall effect is used extensively to study chiral spin textures in various materials. However, the factors controlling its magnitude in technologically-relevant thin films remain uncertain. Using variable-temperature magnetotransport and real-space magnetic imaging in a series of Ir/Fe/Co/Pt heterostructures, here we report that the chiral spin fluctuations at the phase boundary between isolated skyrmions and a disordered skyrmion lattice result in a power-law enhancement of the topological Hall resistivity by up to three orders of magnitude.
View Article and Find Full Text PDFJ Phys Condens Matter
July 2020
We discuss in detail the electron scattering pattern on skyrmion-like magnetic textures in two-dimensional geometry. The special attention is focused on analyzing the scattering asymmetry, which is a precursor of the topological Hall effect. We present analytical results valid in the limiting regimes of strong and weak coupling, we analyze analytically the conditions when the transverse response acquires a quantized character determined by the topological charge of a magnetic texture, we also derive the numerical scheme that gives access to the exact solution of the scattering problem.
View Article and Find Full Text PDFIn this work we manifest that an electrostatic disorder in conducting systems with broken time reversal symmetry universally leads to a chiral ordering of the electron gas giving rise to skyrmion-like textures in spatial distribution of the electron spin density. We describe a microscopic mechanism underlying the formation of the equilibrium chiral spin textures in two-dimensional systems with spin-orbit interaction and exchange spin splitting. We have obtained analytical expressions for spin-density response functions and have analyzed both local and non-local spin response to electrostatic perturbations for systems with parabolic-like and Dirac electron spectra.
View Article and Find Full Text PDFWe propose a new theory of the topological Hall effect (THE) in systems with non-collinear magnetization textures such as magnetic skyrmions. We solve the problem of electron scattering on a magnetic skyrmion exactly, for an arbitrary strength of exchange interaction and the skyrmion size. We report the existence of different regimes of THE and resolve the apparent contradiction between the adiabatic Berry phase theoretical approach and the perturbation theory for THE.
View Article and Find Full Text PDFWe present a theory of electron scattering on a magnetic Skyrmion for the case when the exchange interaction is moderate so that the adiabatic approximation and the Berry phase approach are not applicable. The theory explains the appearance of a topological Hall current in the systems with magnetic Skyrmions, the special importance of which is its applicability to dilute magnetic semiconductors with a weak exchange interaction.
View Article and Find Full Text PDFThe paper gives a rare case of soft tissue chondroma in a 55-year-old female woman who has unsuccessfully received physiotherapeutic procedures for more than 6 months due to misdiagnosis. The patient detected the tumor herself. Clinical and X-ray diagnostic difficulties are considered.
View Article and Find Full Text PDFZh Mikrobiol Epidemiol Immunobiol
October 1987
Zh Mikrobiol Epidemiol Immunobiol
November 1986
Seven-year experience in the methodological guidance of the post-graduate specialization of medical graduates specializing in epidemiology has made it possible for the authors to come to the conclusion on the positive role of the on-the-job training of young specialists for a year after graduation, which is manifested by a shorter time necessary for their professional formation, the development of their capacity for making scientifically grounded, active solutions of practical problems. At the same time some defects, difficulties, and unsolved problems of on-the-job training have been revealed. The authors propose to organize internship also for this category of medical specialists and to carry out the specialization of all sanitary inspectors on the basis of "clinical" sanitary and epidemiological stations.
View Article and Find Full Text PDFZh Mikrobiol Epidemiol Immunobiol
July 1980
The immunogenicity, immunological and epidemiological effectiveness of the subcutaneous, enteral and combined immunizations of the workers at a steel plant with staphylococcal toxoid has been studied. The subcutaneous injection of the adsorbed toxoid in a dose of 0.2 ml by means of the jet injector, model, was accompanied by moderate reactogenicity (the frequency of local reactions was 26.
View Article and Find Full Text PDFZh Mikrobiol Epidemiol Immunobiol
July 1976
For a more complete and proper assessment of the intensity of the epidemic process in infections with polymorphic clinical picture it is suggested, that, along with morbidity analysis one should calculate the affection level and the ratio of the manifest and inapparent forms (infection carrier forms). For this purpose suitable formulas of calculation are recommended. A possibility of the use of this method for evaluation of the intensity of the infectious process in various groups of persons, depending on age, season, etc.
View Article and Find Full Text PDFZh Mikrobiol Epidemiol Immunobiol
February 1975
On the basis of critical survey of literature data and analysis of morbidity of intestinal infections in 5 towns of Donbass for 20 years and also of studying 5148 case histories an attempt is made of rational explantation of the causes of growth during the last years of the incidence of Sonne dysentery salmonelloses, escherichioses and other diseases caused by conditionally-pathogenic microorganisms. The importance of improvement of nomenclature and of statistical classification of intestinal infections was demonstrated.
View Article and Find Full Text PDFZh Mikrobiol Epidemiol Immunobiol
December 1965
Zh Mikrobiol Epidemiol Immunobiol
October 1964
Zh Mikrobiol Epidemiol Immunobiol
June 1964
Med Parazitol (Mosk)
December 1996