Bimeron nanoconfined design

We report on the stabilization of the topological bimeron excitations in confined geometries. The Monte Carlo simulations for a ferromagnet with a strong Dzyaloshinskii-Moriya interaction revealed the formation of a mixed skyrmion-bimeron phase. The vacancy grid created in the spin lattice drastically changes the picture of the topological excitations and allows one to choose between the formation of a pure bimeron and skyrmion lattice. We found that the rhombic plaquette provides a natural environment for stabilization of the bimeron excitations. Such a rhombic geometry can protect the topological state even in the absence of the magnetic field.Comment: 5 pages, 7 figure

Profile approach for recognition of three-dimensional magnetic structures

We propose an approach for low-dimensional visualisation and classification of complex topological magnetic structures formed in magnetic materials. Within the approach one converts a three-dimensional magnetic configuration to a vector containing the only components of the spins that are parallel to the z axis. The next crucial step is to sort the vector elements in ascending or descending order. Having visualized profiles of the sorted spin vectors one can distinguish configurations belonging to different phases even with the same total magnetization. For instance, spin spiral and paramagnetic states with zero total magnetic moment can be easily identified. Being combined with a simplest neural network our profile approach provides a very accurate phase classification for three-dimensional magnets characterized by complex multispiral states even in the critical areas close to phases transitions. By the example of the skyrmionic configurations we show that profile approach can be used to separate the states belonging to the same phase

Study of the resonance α+13C interaction at low energies: Optimization of parameters of the beam shape

About half of all elements heavier than iron are produced in a stellar environment through the s process, which involves a series of subsequent neutron captures and α decays. The reaction 13C(α,n)16O is considered to be the main source of neutrons for the s process at low temperatures in low mass stars in the asymptotic giant branch (AGB). In order to understand better creation of such elements we need to imrove the understanding of creation of such elements, that is to obtain the excitation functions of the 13C (α, α)17O elastic scattering at the initial beam energy 13C from 1.7Mev/A till energies close to zero by using the Thick Target Inverse Kinematics method (TTIK) [1]. The experiment will be conducted in Astana, KZ by using a new heavy ion accelerator DC-60 that provides ion beam with the energy 1.75 MeV/nucleon [1]. To improve the results and reduce errors, the profiling of the beam within the experimental camera is required. In this article, the detailed preparations for this measurement are described

Study of the resonance α+13C interaction at low energies: Optimization of parameters of the beam shape

About half of all elements heavier than iron are produced in a stellar environment through the s process, which involves a series of subsequent neutron captures and α decays. The reaction 13C(α,n)16O is considered to be the main source of neutrons for the s process at low temperatures in low mass stars in the asymptotic giant branch (AGB). In order to understand better creation of such elements we need to imrove the understanding of creation of such elements, that is to obtain the excitation functions of the 13C (α, α)17O elastic scattering at the initial beam energy 13C from 1.7Mev/A till energies close to zero by using the Thick Target Inverse Kinematics method (TTIK) [1]. The experiment will be conducted in Astana, KZ by using a new heavy ion accelerator DC-60 that provides ion beam with the energy 1.75 MeV/nucleon [1]. To improve the results and reduce errors, the profiling of the beam within the experimental camera is required. In this article, the detailed preparations for this measurement are described

Supervised learning magnetic skyrmion phases

We propose and apply simple machine learning approaches for recognition and classification of complex non-collinear magnetic structures in two-dimensional materials. The first approach is based on the implementation of the single-hidden-layer neural network that only relies on the z projections of the spins. In this setup one needs a limited set of magnetic configurations to distinguish ferromag- netic, skyrmion and spin spiral phases, as well as their different combinations in transitional areas of the phase diagram. The network trained on the configurations for square-lattice Heisenberg model with Dzyaloshinskii-Moriya interaction can classify the magnetic structures obtained from Monte Carlo calculations for triangular lattice and vice versa. The second approach we apply, a minimum distance method performs a fast and cheap classification in cases when a particular configuration is to be assigned to only one magnetic phase. The methods we propose are also easy to use for analysis of the numerous experimental data collected with spin-polarized scanning tunneling microscopy and Lorentz transmission electron microscopy experiments.Comment: 9 pages, 14 figures. Accepted for publication in Physical Review

Performance of Water-Based Liquid Scintillator: An Independent Analysis

The water-based liquid scintillator (WbLS) is a new material currently under development. It is based on the idea of dissolving the organic scintillator in water using special surfactants. This material strives to achieve the novel detection techniques by combining theCerenkov rings and scintillation light, aswell as the total cost reduction compared to pure liquid scintillator (LS).The independent light yieldmeasurement analysis for the light yield measurements using three different proton beamenergies (210MeV, 475MeV, and 2000MeV) for water, two different WbLS formulations (0.4% and 0.99%), and pure LS conducted at Brookhaven National Laboratory, USA, is presented. The results show that a goal of ∼100 optical photons/MeV, indicated by the simulation to be an optimal light yield for observing both the Cerenkov ring and the scintillation light from the proton decay in a large water detector, has been achieve

Estimating Patterns of Classical and Quantum Skyrmion States

In this review we discuss the latest results concerning development of the machine learning algorithms for characterization of the magnetic skyrmions that are topologically-protected magnetic textures originated from the Dzyaloshinskii-Moriya interaction that competes Heisenberg isotropic exchange in ferromagnets. We show that for classical spin systems there is a whole pool of machine approaches allowing their accurate phase classification and quantitative description on the basis of few magnetization snapshots. In turn, investigation of the quantum skyrmions is a less explored issue, since there are fundamental limitations on the simulation of such wave functions with classical supercomputers. One needs to find the ways to imitate quantum skyrmions on near-term quantum computers. In this respect, we discuss implementation of the method for estimating structural complexity of classical objects for characterization of the quantum skyrmion state on the basis of limited number of bitstrings obtained from the projective measurements

Random Number Hardware Generator Using Geiger‐Mode Avalanche Photo Detector

This paper presents the physical concept and test results of sample data of the high-speed hardware true random number generator design based on typically used for High Energy Physics hardware. Main features of this concept are the high speed of the true random numbers generation (tens of Mbt/s), miniature size and estimated lower production cost. This allows the use of such a device not only in large companies and government offices but for the end-user data cryptography, in classrooms, in scientific Monte-Carlo simulations, computer games and any other place where large number of true random numbers is required. The physics of the operations principle of using a Geiger-mode avalanche photo detector is discussed and the high quality of the data collected is demonstrated