Search

Your search keyword '"Kuten, S. A."' showing total 179 results
Start Over Author "Kuten, S. A."
179 results on '"Kuten, S. A."'

2. Simulation of indirect 13C-13C J-coupling tensors in diamond clusters hosting the NV center

Author

Nizovtsev, A., Pushkarchuk, A., Kuten, S., Michels, D., Lyakhov, D., Kargin, N., and Kilin, S.

Subjects
Quantum Physics
Abstract

Using the ORCA 5.0.2 software package we have simulated for a first time the full tensors nJKL (K,L=X,Y,Z), describing n-bond J-coupling of nuclear spins 13C in H-terminated diamond-like clusters C10H16 (adamantane) and C35H36 as well as in the cluster C33[NV-]H36 hosting the negatively charged NV- center. We found that, in addition to usually considered isotropic scalar nJ-coupling constant the anisotropic contributions to the nJ-coupling tensor are essential. We have also shown that the presence of the NV center affects the J-coupling characteristics, especially in the case of 13C-13C pairs located near the vacancy of the NV center., Comment: 10 pages, 3 figures, proceeding paper IOCN2022

Published
2022

4. Hidden correlation between absorption peaks in achiral carbon nanotubes and nanoribbons

Author

Saroka, V. A., Pushkarchuk, A. L., Kuten, S. A., and Portnoi, M. E.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

In this paper we study the effect of absorption peak correlation in finite length carbon nanotubes and graphene nanoribbons. It is shown, in the orthogonal {\pi}-orbital tight-binding model with the nearest neighbor approximation, that if the ribbon width is a half of the tube circumference the effect takes place for all achiral ribbons (zigzag, armchair and bearded), and corresponding tubes, starting from lengths of about 30 nm. This correlation should be useful in designing nanoribbon-based optoelectronics devices fully integrated into a single layer of graphene., Comment: 20 pages, 4 figures

Published
2018
Full Text
View/download PDF

5. Non-flipping 13C spins in NV diamond: Hyperfine and Spatial Characteristics by DFT Simulation of the C510[NV]H252 Cluster

Author

Nizovtsev, A. P., Kilin, S. Ya., Pushkarchuk, A. L., Pushkarchuk, V. A., Kuten, S. A., Zhikol, O. A., Schmitt, S., Unden, T., and Jelezko, F.

Subjects
Quantum Physics
Abstract

Single NV centers in diamond coupled by hyperfine interaction to neighboring 13C nuclear spins are now widely used in the emerging quantum technologies as elements of quantum memory adjusted to NV center electron spin qubit. For nuclear spins with low flip-flop rate, single shot readout was demonstrated under ambient conditions. Here we report on the systematic search of such stable NV-13C systems using density functional theory (DFT) to simulate hyperfine and spatial characteristics of all possible NV-13C complexes in the H-terminated cluster C510 [NV]-H252 hosting the NV center. Along with the expected stable NV- axial 13C systems wherein the 13C nuclear spin is located on the NV axis, we found for the first time new families of positions for the 13C nuclear spin exhibiting negligible hyperfine-induced flipping rates due to near-symmetric local spin density distribution. Spatially, these positions are located in the diamond bilayer passing through the vacancy of the NV center and being perpendicular to the NV axis. Analysis of available publications showed that, apparently, some of the predicted non-axial near-stable systems NV-13C have already been observed experimentally. A special experiment done on one of these systems confirmed the prediction made

Published
2017
Full Text
View/download PDF

10. Quantum Memory on 13C–13C Dimers in Diamond with NV Centers: Simulation by Quantum Chemistry Methods.

Author

Nizovtsev, A. P., Pushkarchuk, A. L., Kuten, S. A., Lyakhov, D., Michels, D. L., Gusev, A. S., Kargin, N. I., and Kilin, S. Ya.

Subjects
QUANTUM chemistry, ELECTRON spin states, DIMERS, HYPERFINE coupling, DIAMONDS, SPIN-spin coupling constants
Abstract

Individual electron–nuclear spin systems in solids are promising platforms for implementation of second-generation quantum technologies. The recognized leader among such systems is the negatively charged nitrogen–vacancy color center (NV center) in diamond with hyperfine coupling to nuclear spins of carbon-13 (13C), which are widely used as a quantum memory in emerging quantum technologies because of their weak interaction with the environment. Recently, pairs of 13C–13C nuclei (dimers) in diamond with NV centers have been proposed and actively studied for this purpose because they have extremely long coherence times (minutes at room temperature) in the singlet state. The eigenstates of the spin Hamiltonian of the NV–13C–13C system were found and used to calculate the probabilities of EPR transitions between nuclear-spin sublevels of NV-center states with electron spin projections mS = 0 and mS = –1. The obtained expressions form the basis for choosing the optimal parameters of microwave and radiofrequency pulses transforming a particular dimer into the singlet state. An example of such a prediction for a specific NV–13C–13C spin system using data for the spatial positions of the 13C spins and the internal spin–spin couplings obtained earlier by quantum chemistry methods is presented. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

39. Влияние плотности почвы и характера распределения радионуклидов ¹³⁴Cs и ¹³⁷Cs по профилю при in situ измерениях

Author

Zhukouski, A., Anshakou, O., Nichyparchuk, A., Marozik, P., and Kuten, S.

Subjects
Contaminated soil layer, Плотность почвы, Неравномерное распределение радионуклида, Density of soil, Эффективная толщина, In situ гамма-спектрометр, Загрязненный слой почвы, Effective thickness, Physics::Geophysics, In situ gamma-spectrometer, Non-uniform distribution
Abstract

Periodic radiation monitoring of soils today is a priority task not only for Belarus, but also for Japan, suffered by Fukushima nuclear power plant accident. Use of portable and light spectrometers with ability to perform in situ measurements makes it possible to quickly estimate specific activity of measured radionuclides with required accuracy in particular soil site. Basic information of a gamma radiation source (radionuclides content, effective radius of measurement area and thickness of contaminated layer) can be obtained directly during measurement. The purpose of this research is to test the feasibility of using algorithms for determination of specific activity and thickness of contaminated layer under conditions of soil measurement with variable density parameters and radiocesium distribution in soil. Monte-Carlo simulating allowed to estimate the degree of deviation of the shape of simulated spectra obtained with the use of Monte-Carlo soil model with uniformly distributed radionuclide in it, and for the case when the radionuclide distribution by soil profile can be described by an exponential function. For these cases of natural distribution of radiocesium, the pulse-amplitude spectrum is formed by an effective thickness of the contaminated site, which contains more than 90 % of radionuclides. The developed Monte-Carlo model of a probe and contaminated soil site allows to estimate the effect of the variability of soil density on the total count rate of the pulse-amplitude spectrum. As a result of theoretical estimations, the relationship between the effective radius of contaminated site is determined as a function of soil density. Analysis of the influence of radial zones of the cylindrical gamma source on in situ gamma-spectrometer showed that the main contribution to the total count rate of the pulse-amplitude spectrum is made by the radial zone with radius of up to 40 cm from the center of the probe, regardless of the thickness of the contaminated layer in geometry «Probe is located on the soil surface». A small site facilitates the selection of measurement area of land with a sufficiently flat surface, which is desirable during surveying the territories, especially with complex terrain.

Published
2018

48. Secondary neutrons generated by medical linear electron accelerator

Author

Verenich, K. A., Minenko, V. F., Khrutchinsky, A. A., and Kuten, S. A.

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

Section V. Equipment, Methods and Automation of Nuclear Experiments, Interaction of Nuclear Radiation with the Matter and Applications of Methods of Nuclear Physics

Published
2014

Catalog

Books, media, physical & digital resources
See catalog results