Broken rotation symmetry in the fractional quantum Hall system

We demonstrate that the two-dimensonal electron system in a strong perpendicular magnetic field has stable states which break rotational but not translational symmetry. The Laughlin fluid becomes unstable to these states in quantum wells whose thickness exceeds a critical value which depends on the electron density. The order parameter at 1/3 reduced density resembles that of a nematic liquid crystal, in that a residual two-fold rotation axis is present in the low symmetry phase. At filling factors 1/5 and 1/7, there are states with four- and six-fold axes, as well. We discuss the experimental detection of these phases.Comment: 8 pages, LaTex 3.1, figures attache

Unsupervised landmark analysis for jump detection in molecular dynamics simulations

Molecular dynamics is a versatile and powerful method to study diffusion in solid-state ionic conductors, requiring minimal prior knowledge of equilibrium or transition states of the system's free energy surface. However, the analysis of trajectories for relevant but rare events, such as a jump of the diffusing mobile ion, is still rather cumbersome, requiring prior knowledge of the diffusive process in order to get meaningful results. In this work, we present a novel approach to detect the relevant events in a diffusive system without assuming prior information regarding the underlying process. We start from a projection of the atomic coordinates into a landmark basis to identify the dominant features in a mobile ion's environment. Subsequent clustering in landmark space enables a discretization of any trajectory into a sequence of distinct states. As a final step, the use of the smooth overlap of atomic positions descriptor allows distinguishing between different environments in a straightforward way. We apply this algorithm to ten Li-ionic systems and conduct in-depth analyses of cubic Li$_{7}$La$_{3}$Zr$_{2}$O$_{12}$, tetragonal Li$_{10}$GeP$_{2}$S$_{12}$, and the $\beta$-eucryptite LiAlSiO$_{4}$. We compare our results to existing methods, underscoring strong points, weaknesses, and insights into the diffusive behavior of the ionic conduction in the materials investigated

Transverse Dynamics and Relaxation in Spin-Polarized or Two-Level Fermi Systems

A microscopic theory is proposed for transverse dynamics and zero-temperature attenuation in polarized Fermi liquids. The transport equations are a set of two coupled equations in two ‘‘partial transverse densities,’’ which do not reduce to a single equation in a mixed component of a single-particle distribution. The effective interaction is linked to an irreducible vertex by an integral equation, and cannot be given as a limit of a full vertex. A framework for a generalized nonlocal Landau theory is established. The spectrum of attenuating spin waves is calculated at arbitrary polarizations and densities

Training system for future specialists: quality control

The development ofinnovative strategy of engineers and skilled workers training quality control in educational professional organizations on the principles of social partnershi

Anomalous Spin Dynamics and Relaxation in Fermi Liquids

We explain the anomalous temperature dependence of spin diffusion in liquid 3↑ and 3--4He mixtures. The anomaly is an experimental manifestation of a unique zero-temperature attenuation in the Fermi liquid theory. We extended our microscopic theory of spin dynamics in spin-polarized Fermi liquids to finite temperatures. The zero-temperature attenuation changes the behavior of the spectrum near the singular point. The data indicate that the superfluid transition temperature for 3He in 3--4He mixtures is much lower than the current estimates

Strategic management training of future specialists in the system of higher education: conceptual basis

There has been developed a conceptual model for strategic management based on the vast experience analysis and generalization for management training of future specialists in higher education establishment

Development of Online Master's Degree Course in Education Digitalization Conditions: On BSU Experience

This article presents a study of the development of the online master’s degree course at Belgorod National Research University (BSU) in a context of education digitalization in Russia. It demonstrates the successful introduction of the frameworks of intensity, scalability, and a modular approach to learning, asynchrony, interactivity, automation, openness, and adaptability. We consider the online master’s course as an open information and learning environment that is designed for effective management and monitoring of the educational process. The online master’s degree course at BSU aims to create a flexible and adaptive educational system that meets the needs of the digital economy and ensures the fullest use of the didactic potential of digital technologies. It is proved that to ensure high-quality assimilation of the master’s degree program, the managers of the educational process need to provide pedagogical support to learners. The basis for effective development of online master’s degree course is in availability of online courses (MOOC) placed on online platforms; formation of students’ ICT competence; application of interactive teaching methods; motivational readiness for self-education; readiness of teachers to interact online; available on-line maintenance in the educational process and the possibility of computer networks/Wi-Fi. According to the study, the conditions for the effective development of online master’s degree course in higher education allow: ensuring the personalization of the educational process; involving each student in learning activities; motivating learners at all stages of the learning process; providing the continuous personalized monitoring of students’ learning achievements, giving the prompt feedback to students; ensuring the availability of educational programs for learners who live in remote areas, as well as those with disabilities. Keywords: continuing education digitalization, online learning, e-learning, online master’s degree course, cyberculture, MOO

Learning Interatomic Potentials at Multiple Scales

The need to use a short time step is a key limit on the speed of molecular dynamics (MD) simulations. Simulations governed by classical potentials are often accelerated by using a multiple-time-step (MTS) integrator that evaluates certain potential energy terms that vary more slowly than others less frequently. This approach is enabled by the simple but limiting analytic forms of classical potentials. Machine learning interatomic potentials (MLIPs), in particular recent equivariant neural networks, are much more broadly applicable than classical potentials and can faithfully reproduce the expensive but accurate reference electronic structure calculations used to train them. They still, however, require the use of a single short time step, as they lack the inherent term-by-term scale separation of classical potentials. This work introduces a method to learn a scale separation in complex interatomic interactions by co-training two MLIPs. Initially, a small and efficient model is trained to reproduce short-time-scale interactions. Subsequently, a large and expressive model is trained jointly to capture the remaining interactions not captured by the small model. When running MD, the MTS integrator then evaluates the smaller model for every time step and the larger model less frequently, accelerating simulation. Compared to a conventionally trained MLIP, our approach can achieve a significant speedup (~3x in our experiments) without a loss of accuracy on the potential energy or simulation-derived quantities.Comment: Working paper. 11 pages, 2 figure