KORTES Mission for Solar Activity Monitoring Onboard International Space Station

peer reviewedWe present a description of the recent advances in the development of the KORTES assembly—the first solar oriented mission designed for the Russian segment of the International Space Station. KORTES consists of several imaging and spectroscopic instruments collectively covering a wide spectral range extending from extreme ultraviolet (EUV) wavelengths to X-rays. The EUV telescopes inside KORTES will trace the origin and dynamics of various solar phenomena, e.g., flares, CMEs, eruptions etc. EUV spectra provided by grazing-incidence spectroheliographs will enable precise DEM-diagnostics during these events. The monochromatic X-ray imager will observe the formation of hot plasma in active regions and outside them. The SolpeX module inside KORTES will offer an opportunity to measure fluxes, Doppler shifts and polarization of soft X-ray emission both in lines and continuum. SolpeX observations will contribute to studies of particle beams and chromospheric evaporation. The instrumentation of KORTES will employ a variety of novel multilayer and crystal optics. The deployment of KORTES is planned for 2024

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Axiological distribution of the limited electric power of the household

The structure of household electricity consumption depends on multiple factors. The operation of household electrical networks is possible within the allocated power limit and is restricted by the installed automatic disconnection devices of the power supply network. In conditions of limited allocated electrical power, comfortable living is not possible without prioritized power redistribution. A six-level hierarchical system of electrical power distribution for households has been proposed, incorporating variable priorities. By employing prioritized disconnection principles for groups of electrical appliances, the disconnection of limited household power supply can be avoided while maintaining maximum comfort. The proposed electrical connection scheme for household electrical equipment includes priority relays, time relays, and devices for remote disconnection of secondary appliances. When using heat pumps and heat accumulators for heating systems, a limit of 15 kWh is sufficient for comfortable use of any standard electrical appliances in households with an area of up to 150 square meters

The system of priority distribution of the allocated limited electrical capacity of the household

The structure of household electricity consumption is dependent on many factors, such as time, climate, territorial, historical, social, age, gender, and political factors. Operation of the power grid of households is possible within the allocated power limit and is limited by the devices installed for automatic disconnection of the power supply network. A 6-level hierarchical, with alternating precedence, system of electric power distribution for households is proposed. The highest (first) level is urgent needs and without which in the modern world it is impossible to exist. The second refers to devices to ensure the physiological and social needs of a person, the third is large household appliances. The fourth and fifth levels of the pyramid of household electricity consumption are related to heat supply systems and the concept of thermal inertia of buildings. The sixth is the devices of the lowest priority, supplied with energy according to the residual principle. An example is charging an electric car. The proposed method of distribution of electrical power allows to ensure comfortable living in the household while limiting the total power of the allocated electrical energy

Investigation of electrooptical characteristics of algdas/cdas of waveguide heterostructures with quantum pits

Waveguide heterostructures with quantum pits are considered in the paper aiming at the electrooptical characteristics investigation of waveguide heterostructures with quantum pits. As a result theoretical data about the influence of the interaction of states in a waveguide structure with a non-periodical superlattice on electrooptical properties have been obtained for the first time. The possibility of the instrument use of 2D electron gas effects in a waveguide p-n-heterostructure has been displayed for the first timeAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Plasmonic effects in metal-semiconductor nanostructures

Metal-semiconductor nanostructures represent an important new class of materials employed in designing advanced optoelectronic and nanophotonic devices, such as plasmonic nanolasers, plasmon-enhanced light-emitting diodes and solar cells, plasmonic emitters of single photons, and quantum devices operating in infrared and terahertz domains. The combination of surface plasmon resonances in conducting structures, providing strong concentration of an electromagnetic optical field nearby, with sharp optical resonances in semiconductors, which are highly sensitive to external electromagnetic fields, creates a platform to control light on the nanoscale. The design of the composite metal-semiconductor system imposes the consideration of both the plasmonic resonances in metal and the optical transitions in semiconductors - a key issue being their resonant interaction providing a coupling regime. In this book the reader will find descriptions of electrodynamics of conducting structures, quantum physics of semiconductor nanostructures, and guidelines for advanced engineering of metal-semiconductor composites. These constituents form together the physical basics of the metal-semiconductor plasmonics, underlying many effective practical applications. The list of covered topics also includes the review of recent results, such as the achievement of a strong coupling regime, and the preservation of non-classical statistics of photons in plasmonic cavities combined with semiconductor nanostructures

Bright Single-Photon Emitters with a CdSe Quantum Dot and Multimode Tapered Nanoantenna for the Visible Spectral Range

We report on single photon emitters for the green-yellow spectral range, which comprise a CdSe/ZnSe quantum dot placed inside a semiconductor tapered nanocolumn acting as a multimode nanoantenna. Despite the presence of many optical modes inside, such a nanoantenna is able to collect the quantum dot radiation and ensure its effective output. We demonstrate periodic arrays of such emitters, which are fabricated by focused ion beam etching from a II-VI/III-V heterostructure grown using molecular beam epitaxy. With non-resonant optical pumping, the average count rate of emitted single photons exceeds 5 MHz with the second-order correlation function g(2)(0) = 0.25 at 220 K. Such single photon emitters are promising for secure free space optical communication lines

Bright Single-Photon Sources for the Telecommunication O-Band Based on an InAs Quantum Dot with (In)GaAs Asymmetric Barriers in a Photonic Nanoantenna

We report on single-photon emitters for the telecommunication O-band (1260–1360 nm), which comprise an InAs/(In)GaAs quantum dot with asymmetric barriers, placed inside a semiconductor tapered nanocolumn acting as a photonic nanoantenna. The implemented design of the barriers provides a shift in the quantum dot radiation wavelength towards the O-band, while the nanoantenna collects the radiation and ensures its effective output. With non-resonant optical pumping, the average count rate of emitted single photons exceeds 10 MHz with the second-order correlation function g(2)(0) = 0.18 at 8 K

Towards Bright Single-Photon Emission in Elliptical Micropillars

In recent years, single-photon sources (SPSs) based on the emission of a single semiconductor quantum dot (QD) have been actively developed. While the purity and indistinguishability of single photons are already close to ideal values, the high brightness of SPSs remains a challenge. The widely used resonant excitation with cross-polarization filtering usually leads to at least a two-fold reduction in the single-photon counts rate, since single-photon emission is usually unpolarized, or its polarization state is close to that of the exciting laser. One of the solutions is the use of polarization-selective microcavities, which allows one to redirect most of the QD emission to a specific polarization determined by the optical mode of the microcavity. In the present work, elliptical micropillars with distributed Bragg reflectors are investigated theoretically and experimentally as a promising design of such polarization-selective microcavities. The impact of ellipticity, ellipse area and verticality of the side walls on the splitting of the optical fundamental mode is investigated. The study of the near-field pattern allows us to detect the presence of higher-order optical modes, which are classified theoretically. The possibility of obtaining strongly polarized single-photon QD radiation associated with the short-wavelength fundamental cavity mode is shown

Quantum Dot Photoluminescence Enhancement in GaAs Nanopillar Oligomers Driven by Collective Magnetic Modes

Single photon sources based on semiconductor quantum dots are one of the most prospective elements for optical quantum computing and cryptography. Such systems are often based on Bragg resonators, which provide several ways to control the emission of quantum dots. However, the fabrication of periodic structures with many thin layers is difficult. On the other hand, the coupling of single-photon sources with resonant nanoclusters made of high-index dielectric materials is known as a promising way for emission control. Our experiments and calculations show that the excitation of magnetic Mie-type resonance by linearly polarized light in a GaAs nanopillar oligomer with embedded InAs quantum dots leads to quantum emitters absorption efficiency enhancement. Moreover, the nanoresonator at the wavelength of magnetic dipole resonance also acts as a nanoantenna for a generated signal, allowing control over its radiation spatial profile. We experimentally demonstrated an order of magnitude emission enhancement and numerically reached forty times gain in comparison with unstructured film. These findings highlight the potential of quantum dots coupling with Mie-resonant oligomers collective modes for nanoscale single-photon sources development