Ferromagnetic Josephson switching device with high characteristic voltage

We develop a fast Magnetic Josephson Junction (MJJ) - a superconducting ferromagnetic device for a scalable high-density cryogenic memory compatible in speed and fabrication with energy-efficient Single Flux Quantum (SFQ) circuits. We present experimental results for Superconductor-Insulator-Ferromagnet-Superconductor (SIFS) MJJs with high characteristic voltage IcRn of >700 uV proving their applicability for superconducting circuits. By applying magnetic field pulses, the device can be switched between MJJ logic states. The MJJ IcRn product is only ~30% lower than that of conventional junction co-produced in the same process, allowing for integration of MJJ-based and SIS-based ultra-fast digital SFQ circuits operating at tens of gigahertz.Comment: 10 pages, 4 figure

Revealing Josephson vortex dynamics in proximity junctions below critical current

Made of a thin non-superconducting metal (N) sandwiched by two superconductors (S), SNS Josephson junctions enable novel quantum functionalities by mixing up the intrinsic electronic properties of N with the superconducting correlations induced from S by proximity. Electronic properties of these devices are governed by Andreev quasiparticles [1] which are absent in conventional SIS junctions whose insulating barrier (I) between the two S electrodes owns no electronic states. Here we focus on the Josephson vortex (JV) motion inside Nb-Cu-Nb proximity junctions subject to electric currents and magnetic fields. The results of local (Magnetic Force Microscopy) and global (transport) experiments provided simultaneously are compared with our numerical model, revealing the existence of several distinct dynamic regimes of the JV motion. One of them, identified as a fast hysteretic entry/escape below the critical value of Josephson current, is analyzed and suggested for low-dissipative logic and memory elements.Comment: 11 pages, 3 figures, 1 table, 43 reference

Spectroscopic analysis of metabolic profile in patients with relapsed multiple sclerosis

Introduction. Managing patients with relapsing-remitting multiple sclerosis (RMS) remains a pressing issue. Objective. To detect the reversible metabolic changes of the brain matter in patients with clinically exacerbated RMS and to follow them up after intravenous glucocorticoid (IVGC) treatment. Materials and methods. Neurological examination and neuroimaging in the RMS patients included expanded disability status scale (EDSS) scoring, conventional brain magnetic resonance imaging (MRI), and proton nuclear magnetic resonance spectroscopy (1H-NMR spectroscopy) before and after IVGC treatment. Multivoxel 1H-NMR spectroscopy was used to assess metabolism in the centra semiovale and cingulate gyri. Results. Based on the multivoxel 1H-NMR spectroscopy, relative metabolite concentrations in the grey and white matter statistically differed within the study cohort before and after the IVGC treatment. The N-acetylaspartate/choline ratio significantly recovered and the choline/creatine ratio decreased in the anterior cingulate gyri in 27% of patients. The brainstem function score significantly improved in the metabolic response group as compared to the non-metabolic response group. Conclusion. We should study the potential predictors of RMS activity and the IVGC response to select the RMS relapses when pulse-therapy with IVGCs is definitely indicated. Spectroscopy may reveal RMS pathogenesis variability earlier than conventional MRI

Ultrastrong photon-to-magnon coupling in multilayered heterostructures involving superconducting coherence via ferromagnetic layers

The critical step for future quantum industry demands realization of efficient information exchange between different-platform hybrid systems that can harvest advantages of distinct platforms. The major restraining factor for the progress in certain hybrids is weak coupling strength between the elemental particles. In particular, this restriction impedes a promising field of hybrid magnonics. In this work, we propose an approach for realization of on-chip hybrid magnonic systems with unprecedentedly strong coupling parameters. The approach is based on multilayered microstructures containing superconducting, insulating, and ferromagnetic layers with modified photon phase velocities and magnon eigenfrequencies. The enhanced coupling strength is provided by the radically reduced photon mode volume. Study of the microscopic mechanism of the photon-to-magnon coupling evidences formation of the long-range superconducting coherence via thick strong ferromagnetic layers in superconductor/ferromagnet/superconductor trilayer in the presence of magnetization precession. This discovery offers new opportunities in microwave superconducting spintronics for quantum technologies

Follow-Up After Hip and Knee Arthroplasty: a Review of the Literature and a Report on a Pilot Project at the Vreden National Medical Research Center of Traumatology and Orthopedics

Background. Today in our country, the follow-up of patients after arthroplasty is carried out in accordance with clinical guidelines, the wording of which is based on monographs from 2006, 2008, and 2014, in addition, clinical guidelines for follow-up do not take into account the results of treatment assessed by the patient himself. The purpose of this study was to examine existing systems and develop a proprietary follow-up system for patients after hip and knee arthroplasty. Results. A review of the literature revealed that follow-up of patients after arthroplasty is an unsolved problem, within which there is low coverage, reluctance or forgetfulness of the asymptomatic patient, the problem of accessibility of medical examinations, and an excessive financial burden on the health care system. Since 2022, fixed recommendations for follow-up after arthroplasty have been used in the clinical practice of our center in discharge epicrisis. Recommendations for the frequency of follow-up were formulated by experts based on a comprehensive review of the literature and their own experience. In the first three months, 221 hip and 235 knee evaluation questionnaires were collected through the proposed mechanism, with a progressive increase in the number of questionnaires based on weekly monitoring data. Conclusion. Unfortunately, the outpatient clinic system is not always able to provide qualitative monitoring of patients after arthroplasty due to various reasons, therefore, in our opinion, the implementation of the mechanism of remote monitoring of patients will allow detecting various complications at the stage of early diagnosis, which will contribute to prompt solution of these problems. The remote monitoring system is also an important source of scientific data

Contribution of Processes in SN Electrodes to the Transport Properties of SN-N-NS Josephson Junctions

In this paper, we present a theoretical study of electronic transport in planar Josephson Superconductor–Normal Metal–Superconductor (SN-N-NS) bridges with arbitrary transparency of the SN interfaces. We formulate and solve the two-dimensional problem of finding the spatial distribution of the supercurrent in the SN electrodes. This allows us to determine the scale of the weak coupling region in the SN-N-NS bridges, i.e., to describe this structure as a serial connection between the Josephson contact and the linear inductance of the current-carrying electrodes. We show that the presence of a two-dimensional spatial current distribution in the SN electrodes leads to a modification of the current–phase relation and the critical current magnitude of the bridges. In particular, the critical current decreases as the overlap area of the SN parts of the electrodes decreases. We show that this is accompanied by a transformation of the SN-N-NS structure from an SNS-type weak link to a double-barrier SINIS contact. In addition, we find the range of interface transparency in order to optimise device performance. The features we have discovered should have a significant impact on the operation of small-scale superconducting electronic devices, and should be taken into account in their design

Design of a New Silver Jewelry Alloy White 925 Sample for Production Chains

На основании анализа научно-технической литературы и теоретических исследований путем построения политермических разрезов многокомпонентных систем предложено два состава лигатур для выплавки новых сплавов на основе серебра. В статье представлены результаты опытно-промышленных исследований по получению и обработке новых сплавов. Проведена оценка свойств и структуры полученных литых и деформированных полуфабрикатов из новых серебряных ювелирных сплавов 925-й пробыBased on the analysis of scientific literature and theoretical studies by constructing polythermal incisions of multicomponent systems, offered two of ligatures for the smelting of new alloys based on silver. The article presents the results of pilot studies on acquisition and processing of new alloys. The evaluation of the properties and structure of the obtained cast semi-finished products of the new silver jewelry alloys 92