Propagating spin-wave spectroscopy in nanometer-thick YIG films at millikelvin temperatures

Performing propagating spin-wave spectroscopy of thin films at millikelvin temperatures is the next step towards the realisation of large-scale integrated magnonic circuits for quantum applications. Here we demonstrate spin-wave propagation in a $100\,\mathrm{nm}$-thick yttrium-iron-garnet film at the temperatures down to $45 \,\mathrm{mK}$, using stripline nanoantennas deposited on YIG surface for the electrical excitation and detection. The clear transmission characteristics over the distance of $10\,\mu \mathrm{m}$ are measured and the subtracted spin-wave group velocity and the YIG saturation magnetisation agree well with the theoretical values. We show that the gadolinium-gallium-garnet substrate influences the spin-wave propagation characteristics only for the applied magnetic fields beyond $75\,\mathrm{mT}$, originating from a GGG magnetisation up to $47 \,\mathrm{kA/m}$ at $45 \,\mathrm{mK}$. Our results show that the developed fabrication and measurement methodologies enable the realisation of integrated magnonic quantum nanotechnologies at millikelvin temperatures.Comment: 6 pages, 5 figure

Atomic data on inelastic processes in low-energy manganese-hydrogen collisions

Aims. The aim of this paper is to calculate cross sections and rate coefficients for inelastic processes in low-energy Mn + H and Mn+ + H− collisions, especially, for processes with high and moderate rate coefficients. These processes are required for non-local thermodynamic equilibrium (non-LTE) modeling of manganese spectra in cool stellar atmospheres, and in particular, for metal-poor stars. Methods. The calculations of the cross sections and the rate coefficients were performed by means of the quantum model approach within the framework of the Born-Oppenheimer formalism, that is, the asymptotic semi-empirical method for the electronic MnH molecular structure calculation followed by the nonadiabatic nuclear dynamical calculation by means of the multichannel analytic formulas. Results. The cross sections and the rate coefficients for low-energy inelastic processes in manganese-hydrogen collisions are calculated for all transitions between 21 low-lying covalent states and one ionic state. We show that the highest values of the cross sections and the rate coefficients correspond to the mutual neutralization processes into the final atomic states Mn(3d54s(7S)5s e 6S), Mn(3d54s(7S)5p y 8P°), Mn(3d54s(7S)5s e 8S), Mn(3d54s(7S)4d e 8D) [the first group], the processes with the rate coefficients (at temperature T = 6000 K) of the values 4.38 × 10-8, 2.72 × 10-8, 1.98 × 10-8, and 1.59 × 10-8 cm3/ s, respectively, that is, with the rate coefficients exceeding 10-8 cm3/ s. The processes with moderate rate coefficients, that is, with values between 10-10 and 10-8 cm3/ s include many excitation, de-excitation, mutual neutralization and ion-pair formation processes. In addition to other processes involving the atomic states from the first group, the processes from the second group include those involving the following atomic states: Mn(3d5(6S)4s4p (1P°) y 6P°), Mn(3d54s(7S)4d e 6D), Mn(3d54s(7S)5p w 6P°), Mn(3d5(4P)4s4p (3P°) y 6D°), Mn(3d5(4G)4s4p (3P°) y 6F°). The processes with the highest and moderate rate coefficients are expected to be important for non-LTE modeling of manganese spectra in stellar atmospheres

Problems of Legal Regulation of Robotics and Artificial Intelligence from the Psychological Perspective

The article analyzes the main problems and contradictions in the formation of legal regimes for the regulation of robotics, artificial intelligence and other innovative technologies of our time. The work content shows the unpreparedness of modern legal science and practice to conceptual and legal design, legal and technical development of the regulatory legal acts aimed at the legislative fixation and regulation of the processes of using artificial intelligence and robots in public relations, as well as definition of responsibility and appropriate protection modes of legitimate interests, rights, freedoms in the system of personality - society - state. The subject of this study is the resolution of these problems and contradictions, as well as the identification of directions for the formation of a legal framework for the regulation of modern innovative technologies and digital processes unfolding in the modern society. The authors distinguish and analyze two consecutive stages: 1) development and introduction of necessary changes in the existing branches of Russian law; 2) conceptual-legal and doctrinal-legal formulation of key development priorities, as well as creation of a new integrated branch of law - robotics law, which has an independent subject and method of legal regulation.El artículo analiza los principales problemas y contradicciones en la formación de regímenes legales para la regulación de la robótica, la inteligencia artificial y otras tecnologías innovadoras de nuestro tiempo. El contenido del trabajo muestra la falta de preparación de la ciencia y práctica legal moderna para el diseño conceptual y legal, el desarrollo legal y técnico de los actos legales regulatorios destinados a la fijación legislativa y la regulación de los procesos de uso de inteligencia artificial y robots en las relaciones públicas, así como definición de responsabilidad y modos apropiados de protección de intereses legítimos, derechos, libertades en el sistema de personalidad - sociedad - estado. El tema de este estudio es la resolución de estos problemas y contradicciones, así como la identificación de direcciones para la formación de un marco legal para la regulación de tecnologías modernas innovadoras y procesos digitales que se desarrollan en la sociedad moderna. Los autores distinguen y analizan dos etapas consecutivas: 1) desarrollo e introducción de los cambios necesarios en las ramas existentes de la ley rusa; 2) formulación conceptual-legal y doctrinal-legal de prioridades clave de desarrollo, así como la creación de una nueva rama integrada del derecho: la ley de robótica, que tiene un tema y un método de regulación legal independientes

Taxonomic Composition of Protist Communities in the Coastal Stratified Lake Kislo-Sladkoe (Kandalaksha Bay, White Sea) Revealed by Microscopy

Lake Kislo-Sladkoe is a stratified water body partly isolated from the White Sea. Perennial meromixis in the lake irregularly alternates with mixing events. Taking into account that the protists of Arctic coastal stratified water bodies are understudied, we evaluated for the first time the vertical structure, species richness, and diversity of protists assigned to different taxonomic groups in Lake Kislo-Sladkoe using light, luminescent, and scanning electron microscopy. To test the research hypothesis that a mixing event affects the vertical stratification and species composition of protists in a stratified lake, we compared the protist communities of Lake Kislo-Sladkoe in two extremely different states: strong meromixis vs. full vertical mixing. A total of 97 morphologically distinct phototrophic, heterotrophic, and mixotrophic protists were revealed with the most diverse supertaxa SAR (59), Obazoa (9), and Excavates (14). The hidden diversity of protists (43 species) was a bit less than the active diversity (54 species). A taxonomic list and micrographs of cells for the observed protists are provided. The majority of species revealed are cosmopolitan or widespread in the northern sea waters. The vertical patterns of protist communities were absolutely different in 2018 and 2021. In July 2018, clearly distinct protist communities inhabited different layers of the lake. Bloom of cryptophyte Rhodomonas cf. baltica was detected in chemocline, whereas the maximum density of its grazers was observed in adjacent layers, mainly dinoflagellates Gymnodinium sp. and Scrippsiella trochoidea, as well as a ciliate Prorodon sp. In 2021 due to the recent mixing of lake and seawater, there were no distinct communities in the water column except the superficial 0–1 m layer of fresh water

All-Dielectric Nanophotonics Enables Tunable Excitation of the Exchange Spin Waves

Launching and controlling magnons with laser pulses opens up new routes for applications including optomagnetic switching and all-optical spin wave emission and enables new approaches for information processing with ultralow energy dissipation. However, subwavelength light localization within the magnetic structures leading to efficient magnon excitation that does not inherently absorb light has still been missing. Here, we propose to marriage the laser-induced ultrafast magnetism and nanophotonics to efficiently excite and control spin dynamics in magnetic dielectric structures. We demonstrate that nanopatterning by a 1D grating of trenches allows localization of light in spots with sizes of tens of nanometers and thus launch the exchange standing spin waves of different orders. The relative amplitude of the exchange and magnetostatic spin waves can be adjusted on demand by modifying laser pulse polarization, incidence angle, and wavelength. Nanostructuring of the magnetic media provides a unique possibility for the selective spin manipulation, a key issue for further progress of magnonics, spintronics, and quantum technologies