Abstract
Two-dimensional electron systems in a quantizing magnetic field are regarded as of exceptional interest, considering the possible role of anyons—quasiparticles with non-boson and non-fermion ...statistics—in applied physics. To this day, essentially none but the fractional states of the quantum Hall effect (FQHE) have been experimentally realized as a system with anyonic statistics. In determining the thermodynamic properties of anyon matter, it is crucial to gain insight into the physics of its neutral excitations. We form a macroscopic quasi-equilibrium ensemble of neutral excitations - spin one anyon complexes in the Laughlin state
ν
= 1/3, experimentally, where
ν
is the electron filling factor. The ensemble is found to have such a long lifetime that it can be considered the new state of anyon matter. The properties of this state are investigated by optical techniques to reveal its Bose properties.
A calculation scheme has been developed to determine energies of neutral excitations with spin 1 in a Laughlin liquid at a filling factor of 1/3. The parameters of the confining potential of an ...electron system in GaAs/AlGaAs quantum wells, as well as regions of magnetic fields, at which spin-1 excitations are the lowest in energy are calculated.
The temperature dependence of the resonant light reflection spectra from the Laughlin liquid in the 1/3 fractional quantum Hall state is measured. It is shown that the resonant reflection lines under ...conditions corresponding to the formation of the fractional quantum Hall state have a cooperative nature, and their energies do not obey the requirements of the “hidden symmetry.” The energies of spin excitations in the Laughlin liquid are measured using the resonant reflection spectra, and the results of the experiment are compared to the results obtained by solving the Schrödinger equation for several particles.
New 1-aza-3,5-diphosphorinanes have been synthesized as a mixture of
RR
/
SS-
and
RS
-isomers via the reaction of bis(phenylphosphanyl)methane, paraformaldehyde, isopropylamine, of benzhydrylamine.
An investigation is performed of the structure of time-resolved Kerr rotation in two-dimensional electron systems with many-particle Coulomb interaction. It is shown that the spin stiffness in ...fractional spin-unpolarized state ν = 3/2 is close to that of a quantum Hall ferromagnet, independently confirming the local incompressibility of state ν = 3/2.
Two-dimensional electronic systems in a quantizing magnetic field are of great interest when using quasiparticles with non-Bose and non-Fermi (anyon) statistics in solving problems of applied ...physics. The fractional quantum Hall effect states have so far been the only candidates for the role of quasiparticle systems with anyon statistics. Nonequilibrium macroscopic ensembles of neutral excitations in the 1/3 fractional quantum Hall effect are created to determine the statistical and thermodynamic properties of anyon systems and the applicability of anyons in solving technological tasks. It is found these ensembles have such long periods of relaxation they may be considered new quasi-equilibrium states of anyon matter.
The spin coherence of two-dimensional electrons is determined by two independent mechanisms: a single particle relaxation owing to spatially fluctuating magnetic field, and a many-particle exchange ...interaction maintaining collective precession of the electron spins with a common Larmor frequency. In this study, we investigate the structure of a time-resolved Kerr rotation signal for the different spin states of two-dimensional electron system subjected to the quantizing magnetic field. At low temperatures, when spin–spin correlations define the ground state of the two-dimensional electron system, our data show a nonlinear damping of Larmor oscillations. The amplitude and the correlation length of the fluctuating magnetic field acting on individual electron spins are estimated.
•The structure of time-resolved Kerr rotation signal is studied.•Nonlinear damping of Larmor oscillations in 2DES is observed.•Independent confirmation of the local incompressibility in the state ν = 3/2 is found.
Prehistoric monuments often constitute evident landmarks and sometimes, after falling into disuse, fascinated local people enough to stimulate speculations about their origin over time. According to ...legend, the Hill of Udine (NE Italy) was built by Attila the Hun's soldiers, but its origin (natural or anthropogenic) has been debated until now. Our research analyzed five new 40-m long stratigraphic cores, investigating for the first time the total thickness of the hill and compared the data with the available archaeological information. Moreover, we considered other hills and mounds in northern Italy and other European regions where folklore traditions relate their origin to Attila. The geoarchaeological and ethnographic data prove that the Hill of Udine is a Bronze Age anthropogenic mound erected between 1400 and 1150 BCE and that, later, folklore has transformed the ancestral memory of its origin into legend. By measuring 30 m in height and over 400,000 m
in volume, the flat-topped hill is the largest prehistoric mound in Europe. This discovery reveals unprecedented skills in earth construction and confirms significant anthropogenic modifications of the environment during Bronze Age.
Digital pathology has come a long way in terms of creating tools to improve existing diagnostic approaches. However, several pathology fields, such as neuropathology, are still characterized by low ...coverage from machine learning tools and neural network analysis, which may be due to the complexity of the internal cellular and molecular structure of the corresponding neoplasms, including glioblastomas.
In the framework of this study, using advanced proprietary tools for obtaining images of histological slides and their deep morphometric analysis, we studied samples of 198 patients with glioblastoma with the selection of morphometric cell clusters. Also, cells of each cluster were isolated, and their proliferative, migratory, invasive activity, survival ability, aerobic glycolysis activity, and chemo- and radioresistance were studied.
Four morphometric clusters were identified, including small-cell cluster, paracirculonuclear cluster, hypochromic cluster, and macronuclear cluster, which significantly differed in morphometric parameters and functional parameters. Hypochromic cluster cells demonstrated the highest proliferation activity; macronuclear cluster was the most active glucose consumer; paracirculonuclear cluster had the most prominent migratory and invasive activity and hypoxia resistance; small-cell cluster demonstrated predominantly average values of all parameters. Moreover, additional analysis revealed the presence of a separate subcluster of stem cell elements that correspond in their molecular properties to glioma stem cells and are present in all four clusters. It also turned out that several key molecular parameters of glioblastoma, such as mutational modifications in the EGFR, PDGFRA, and NF1 genes, along with the molecular GBM subtype, are significantly correlated with the identified cell clusters.
Thus, the results represent an up-and-coming innovation in the practical field of digital pathology and fundamental questions of glioma carcinogenesis.
•Fundamentally new method of glioblastoma morphometry has been created.•This method was used to determine 130 morphometric parameters for each cell.•Four morphometric cell clusters were identified according to these parameters.•Molecular properties of glioblastoma correlated with isolated cell clusters.
Given the growing role of technological foresight as a tool for reconciling visions, goals and ways of STI development in an era of rapid technological change and global challenges, the approach to ...foresight research to select priorities for science and innovation in Ukraine for 2022–2026 has been improved. It takes into account a wide range of national targets for achieving SDGs by 2030. The developed Methodological recommendations provided a thorough analysis of more than 3,000 potentially acceptable technological and innovative proposals. The approach to setting STI priorities is new for Ukraine and involves a consistent process of selecting the top 30 most acceptable proposals in each of the seven thematic areas through five stages of discussions and evaluations. The result was the formation of a database of technology passports and developments on the experts’ proposals, their selection by practitioners, ranking, evaluation in terms of the potential of Ukrainian science and relevance in terms of world science and new technologies using international databases. They are the basis for decisions by the Expert Councils and the High-Level Working Group on key thematic areas and the preparation of a relevant draft government decision. Despite the conditions of quarantine, for the first time more than 2,500 experts from science, business, state and public organizations took part in the discussions, which is the basis for impartial and public decision-making. To strengthen the role of foresight as a tool for public planning and management in the field of STI, it is proposed to develop a STI roadmap as part of a research and innovation strategy for smart specialization (RIS 3) at the national level.
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