Modern Tendencies of Digitalization of the Financial Services Sphere

Krylov, Denys,Papaika, Oleksandr,Panchenko, Olena,Pylevych, Dmytro,Kozlianchenko, Olena,Konoplia, Nataliia International Journal of Computer ScienceNetwork S 2022 International journal of computer science and netw Vol.22 No.2

The article is devoted to clarifying current trends in the digitalization of financial services. To this end, the evolution of this process in the financial sector was studied and six stages of its development were identified. The components of successful implementation of digitalization in the field of financial services and its tasks are outlined. It was found that fintech companies, which work to achieve effective interaction between the financial sector and innovative technologies in the use of mobile applications in order to most fully and quickly meet the needs of customers with financial services, are of great importance for the formation and development of digitalization in financial services. Current trends in the digitalization of financial services in Ukraine based on the use of fintech in general and banking institutions in particular are presented.

High Blocking Temperature of Magnetization and Giant Coercivity in the Azafullerene Tb ₂ @C ₇₉ N with a Single‐Electron Terbium–Terbium Bond

Velkos, Georgios,Krylov, Denis S.,Kirkpatrick, Kyle,Spree, Lukas,Dubrovin, Vasilii,Bü,chner, Bernd,Avdoshenko, Stanislav M.,Bezmelnitsyn, Valeriy,Davis, Sean,Faust, Paul,Duchamp, James,Dorn, Harry John Wiley and Sons Inc. 2019 Angewandte Chemie. international edition Vol.58 No.18

<P><B>Abstract</B></P><P>The azafullerene Tb<SUB>2</SUB>@C<SUB>79</SUB>N is found to be a single‐molecule magnet with a high 100‐s blocking temperature of magnetization of 24 K and large coercivity. Tb magnetic moments with an easy‐axis single‐ion magnetic anisotropy are strongly coupled by the unpaired spin of the single‐electron Tb−Tb bond. Relaxation of magnetization in Tb<SUB>2</SUB>@C<SUB>79</SUB>N below 15 K proceeds via quantum tunneling of magnetization with the characteristic time <I>τ</I><SUB>QTM</SUB>=16 462±1230 s. At higher temperature, relaxation follows the Orbach mechanism with a barrier of 757±4 K, corresponding to the excited states, in which one of the Tb spins is flipped.</P>

Home-built sub-Kelvin scanning tunneling microscope with electron spin resonance capability

Jiyoon Hwang,Denis Krylov,Taehong Ahn,Lei Fang,Kyungju Noh,Andreas J. Heinrich,Yujeong Bae 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.1

Scanning tunneling microscopy is a powerful tool to characterize the electronic and magnetic properties of atomic scale structures on a surface. Recent advances in increasing energy resolutions have been achieved functionalizing the STM tip by a well-characterized molecule [1,2] or integrating electron spin resonance with STM (ESR-STM) [3]. We present the design and performance of home-built STM with high frequency cabling, which is incorporated with a Joule-Thomson refrigerator and 2-axes vector magnets. Applying high frequency (microwave) electric fields to the STM junction through 50 Ohm coaxial cables causes significant loss of insertion power due to the impedance mismatch at the STM junction of ~1 GOhm, which limits the frequency range of applicable microwaves. To overcome this limitation, we introduced a microwave antenna and terminated the cable at 50 Ohm. Applying microwaves to the antenna rather than the STM tip allows us to reduce the formation of standing waves as well as to increase the transmission. Our work shows using the specially designed mechanical damper and optimizing the electrical noise levels provide the outstanding performance of STM for the single atom ESR experiment.

Single-Electron Lanthanide-Lanthanide Bonds Inside Fullerenes toward Robust Redox-Active Molecular Magnets

Liu, Fupin,Spree, Lukas,Krylov, Denis S.,Velkos, Georgios,Avdoshenko, Stanislav M.,Popov, Alexey A. American Chemical Society 2019 Accounts of chemical research Vol.52 No.10

<P><B>Conspectus</B></P><P>A characteristic phenomenon of lanthanide-fullerene interactions is the transfer of metal valence electrons to the carbon cage. With early lanthanides such as La, a complete transfer of six valence electrons takes place for the metal dimers encapsulated in the fullerene cage. However, the low energy of the σ-type Ln-Ln bonding orbital in the second half of the lanthanide row limits the Ln<SUB>2</SUB> → fullerene transfer to only five electrons. One electron remains in the Ln-Ln bonding orbital, whereas the fullerene cage with a formal charge of −5 is left electron-deficient. Such Ln<SUB>2</SUB>@C<SUB>80</SUB> molecules are unstable in the neutral form but can be stabilized by substitution of one carbon atom by nitrogen to give azafullerenes Ln<SUB>2</SUB>@C<SUB>79</SUB>N or by quenching the unpaired electron on the fullerene cage by reacting it with a chemical such as benzyl bromide, transforming one sp<SUP>2</SUP> carbon into an sp<SUP>3</SUP> carbon and yielding the monoadduct Ln<SUB>2</SUB>@C<SUB>80</SUB>(CH<SUB>2</SUB>Ph). Because of the presence of the Ln-Ln bonding molecular orbital with one electron, the Ln<SUB>2</SUB>@C<SUB>79</SUB>N and Ln<SUB>2</SUB>@C<SUB>80</SUB>(R) molecules feature a unique single-electron Ln-Ln bond and an unconventional +2.5 oxidation state of the lanthanides.</P><P>In this Account, which brings together metallofullerenes, molecular magnets, and lanthanides in unconventional valence states, we review the progress in the studies of dimetallofullerenes with single-electron Ln-Ln bonds and highlight the consequences of the unpaired electron residing in the Ln-Ln bonding orbital for the magnetic interactions between Ln ions. Usually, Ln···Ln exchange coupling in polynuclear lanthanide compounds is weak because of the core nature of 4f electrons. However, when interactions between Ln centers are mediated by a radical bridge, stronger coupling may be achieved because of the diffuse nature of radical-based orbitals. Ultimately, when the role of a radical bridge is played by a single unpaired electron in the Ln-Ln bonding orbital, the strength of the exchange coupling is increased dramatically. Giant exchange coupling in endohedral Ln<SUB>2</SUB> dimers is combined with a rather strong axial ligand field exerted on the lanthanide ions by the fullerene cage and the excess electron density localized between two Ln ions. As a result, Ln<SUB>2</SUB>@C<SUB>79</SUB>N and Ln<SUB>2</SUB>@C<SUB>80</SUB>(CH<SUB>2</SUB>Ph) compounds exhibit slow relaxation of magnetization and exceptionally high blocking temperatures for Ln = Dy and Tb. At low temperatures, the [Ln<SUP>3+</SUP>-e-Ln<SUP>3+</SUP>] fragment behaves as a single giant spin. Furthermore, the Ln-Ln bonding orbital in dimetallofullerenes is redox-active, which allows its population to be changed by electrochemical reactions, thus changing the magnetic properties because the change in the number of electrons residing in the Ln-Ln orbital affects the magnetic structure of the molecule.</P> [FIG OMISSION]</BR>

Integrated Model of the Higher Education Financing Under the Quadruple Helix Concept

Kholiavko, Nataliia,Zhavoronok, Artur,Shaposhnykov, Kostiantyn,Krylov, Denys,Morozova, Liudmyla,Babiak, Nataliia International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.7

Rapid growth of the higher education role in ensuring the socio-economic and innovative development of the national economy in the context of the development of the information society and the knowledge economy is observed. Achieving positive synergistic effects of the higher education development requires proper funding for university education and research. The existing funding models for national higher education systems in a number of developing countries need modernization in accordance with the modern challenges of economic and innovative development. The purpose of the article is to formulate theoretical - methodological and applied foundations for the development and implementation of the integrated model of the higher education financing under the Quadruple Helix concept. At the center of the developed model are the areas of interaction identified by the authors, namely: Personnel, Science, Management, Innovation, Social area. This made it possible to specify the interests of all stakeholders and orient the activities of higher education institutions to the satisfaction of these interests. Effective implementation of the integrated Model of the higher education financing requires increasing the level of investment attractiveness and practical value of university research; activation of innovative development of enterprises; state stimulation of business participation in university research and education; harmonization of current legislation with EU standards. Implementation of the Model will diversify sources of funding for universities, increase their level of economic security and achieve integrated synergies from the interaction of universities, business, government and the public (as the main stakeholders within the Quadruple Helix concept).

Erbium on MgO(100)/Ag(100) as candidate for single-atom-qubit

Stefano Reale,Jiyoon Hwang,Jeongmin Oh,Aparajita Singha,Safa L. Ahmed,Denis Krylov,Luciano Colazzo,Christoph Wolf,Carlo S. Casari,Alessandro Barla,Edgard Fernandes,Francois Patthey,Marina Pivetta,Stef 한국자기학회 2023 한국자기학회 학술연구발표회 논문개요집 Vol.33 No.1

The Influence of Human Capital on GDP Dynamics: Modeling in the COVID-19 Conditions

Derii, Zhanna,Zosymenko, Tetiana,Shaposhnykov, Kostiantyn,Tochylina, Yuliia,Krylov, Denys,Papaika, Oleksandr International Journal of Computer ScienceNetwork S 2022 International journal of computer science and netw Vol.22 No.3

COVID-19 struck labor markets around the world, exposing and exacerbating the gender inequalities within the human capital structure. The last, in its turn, jeopardizes the return of the national economies to the growth trajectory undermined by pandemic impact. The authors assume that COVID-19 disproportionately affected the employment rates of women and men, which led to increased gender inequality in the labor market, which, in turn, affected GDP growth rates in the EU. To prove this hypothesis two research questions are discovered: 1) whether there was a different correlation between the number of COVID-19 cases in the EU and indicators of the labor market for women and men; and 2) whether there was a link between the growth of gender inequality in the EU labor market and the GDP dynamics in these countries. The analysis of the correlation between the number of cases of COVID-19 and indicators of the labor market in the EU revealed faster growth of women's unemployment rates compared to men's ones as the COVID-19 incidence unfolded. Multiple linear regression and factor analysis have been used to investigate the influence of gender inequality in the labor market on GDP dynamics. Despite the methodological limitations, the proposed model is both a sound argument and an analytical basis in favor of gender-responsive economic recovery backed by the systematic and consistent gender equality policy of a government.

Single atomic spin sensing of magnetic interactions in a tunnel junction

Jinkyung Kim,Won-jun Jang,Thi Hong Bui,Deung-Jang Choi,Christoph Wolf,Fernando Delgado,Yi Chen,Denis Krylov,Soonhyeong Lee,Sangwon Yoon,Christopher P. Lutz,Andreas J. Heinrich,Yujeong Bae 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.1

Single spins are widely regarded as a leading candidate for realizing next-generation quantum devices for sensing and quantum information processing. Detection and coherent control of single spins require to localize single spins and characterize its magnetic surroundings. Scanning tunneling microscopy in combination with electron spin resonance (ESR-STM) technique [1] enables a direct access to the quantum states of single magnetic atoms or molecules on surfaces. Using ESR-STM, we investigated spin resonance of hydrogenated Ti (TiH) atoms adsorbed on bridge binding site of MgO in a two-dimensional vector magnetic field. Here, the spin 1/2 TiH atom with no magnetic anisotropy was employed as a probe of magnetic environments at the tunnel junction. We found both ESR frequency and amplitude change as a function of the angle of vector magnetic fields. The resonance frequency varied by different vector magnetic fields indicates an anisotropy of the g-factor, resulting from the variation of angular momentum contributions due to the crystal fields. We developed a stereoscopic way to unravel the g-factor along the three principal axes. Moreover, ESR amplitude dependence on the direction of magnetic fields provides the further understanding of ESR mechanisms, which results from two factors, tunneling magnetoresistance (TMR) effect at the spin-polarized STM junction and the transverse magnetic field to drive ESR. Our results will enable to predict ESR active spin centers on different substrates as well as in other quantum-nanoscience platforms.