Abstract: We theorize a quantum memory based on the dark-state polariton field, formed by the superposition of atomic and photonic states of a travelling probe laser pulse under the application of a standing wave modes of a dominant control laser pulse using a lambda-level scheme Electromagnetically Induced Transparency in a solid medium. We show how an enhancement in the storage time for the pulse is achieved by eliminating pulse broadening due to diffusion. At last, we propose an experiment that can help realise the storage of a probe pulse in the hyperfine levels 3H4 ↔1D2 of Pr3+: Y2SiO5, cryogenically cooled at 4.5 K. We also discuss multiple applications the storage of the quantum states the pulse probe with a prolonged time interval must have.

Abstract: A novel approach was presented in this study where molecular dynamics and Monte Carlo methods were applied to subatomic particles to simulate an atom using pseudo potentials. Pseudo potentials were developed for subatomic particles by conceptualizing them as conventional particles, exhibiting attractive and repulsive forces between them, ensuring the stability of an atom. A stable nucleus was formed at the center with electrons distributed around, resulting in the formation of an atom. Subatomic particle simulations impart a comprehensive perspective and a profound understanding of electron trajectories that correlates with atomic properties such as electron energies and atomic radius. These approaches intricately capture the impact of protons and neutrons motion in the nucleus on electron trajectories. Hydrogen and carbon atoms were considered, and their analyses were reported in this study. Time step for carbon atom simulation was calculated from dimensionless variables and found to be 1.67 attoseconds. The Pilot-wave theory was implemented to simulate the wave nature of subatomic particles in an atom. Electrons motion were guided by the interference pattern produced by the electron and proton aether medium waves. Molecular dynamics simulations on subatomic particles were implemented on an oxygen molecule, giving insights into electronic structures with electron trajectories shared by two atoms.

Abstract: As one of the most accurate instruments in history, the optical clock will be used as the measuring equipment for the next generation of seconds. The demand for miniaturization of optical clock is progressively urgent. In this paper, a multi-channel radio frequency module with a 20% volume of the commercial module is designed and implemented for the transportable 40Ca+ ion optical clock. Based on the double crystal oscillator interlocking technique，1 GHz low-phase noise reference source is developed for direct digital synthesis. By simulation and optimization of the signal link design, a frequency range of the low-phase noise RF signal can reach 0-400 MHz with a 4 μHz resolution. Through two-stage power amplified with different kinds of filters, it can get an output power up to +33 dBm (2 W) at 100 MHz with a 25 dBc/Hz phase noise lower than the commercial module at 1 Hz, and its third harmonic suppression ratio has been reduced by more than 20 dBm at the frequency point of 300 MHz. This multi-channel RF module is used for the power stability and timing control test of 729 nm clock laser, to meet the requirements of the transportable 40Ca+ optical clock. Without this, this module can also be applied to other quantum systems such as quantum absolute gravimeter, quantum gyro and quantum computer.

Abstract: Revealing the structure of atoms and molecules has always been one of the important research goals in the field of quantum mechanics. The currently well-known atomic and molecular structure theories include Rutherford's planetary model, Bohr Sommerfeld atomic structure model, as well as atomic orbital theory, hybrid orbital theory, and molecular orbital theory. However, although these theories can explain atomic or molecular structures to some extent, they all have their own shortcomings, and there is currently no unified theory of atomic and molecular structures established. Here, we propose the Dynamic Entity Model of Electron Orbits, the Electron Spin Theory, and the Spatial Configuration Theory of Electron Orbits. Based on these new concepts and theories, we rearranged the extranuclear electrons of all elements in the periodic table, and explained the structure of atoms, the physical mechanisms of molecular formation, and the spatial structure of molecules. The theories of atomic and molecular structures based on quantum mechanics are often complex, difficult to understand, and inconsistent, while our new concepts and theories are based on classical physics and have the characteristics of being simple, intuitive, and easy to understand, and can logically and consistently explain the structure of atoms and molecules. Therefore, we have established a unified atomic and molecular structure theory based on the framework of classical physics, which has important scientific significance and application value.

Abstract: In this work, we present a new set of transition probabilities for experimentally classified spectral lines in the Os VI spectrum. To do this, two independent computational approaches based on the pseudo-relativistic Hartree-Fock including core-polarization effects (HFR+CPOL) and fully relativistic Multiconfiguration Dirac-Hartree-Fock (MCDHF) methods were used, the detailed comparison of the results obtained with these two approaches allowing us to estimate the quality of the calculated radiative parameters. These atomic data, corresponding to 367 lines of five times ionized osmium between 438.720 and 1486.275 Å, are expected to be useful for the analysis of the spectra emitted by fusion plasmas in which osmium could appear as a result of transmutation by neutron bombardment of tungsten used as component of the reactor wall, such as the ITER divertor.

Abstract: New silicon allotropes, variants of bct-Si4, formed by Si4 rings, and Si8 cubes, have been derived, observing several allotropes of graphene, such as: C4 - 10I, C4 -12, and C4 - 8R1. The first two forms are composed of two and three flat, fused C4 rings: C 6 and C 8; joined to four other groups C6, in the first, and C8, in the second, allotrope variant. The C4 - 8 - R phase would be dormant by diatomic carbon chains, linked to C6 groups, formed by two fused carbon rings, C4. These sp3 three-dimensional allotropes, show variants of the bct - C 4, formed by flat rings, C 4 and cubes, C 8, independent and fused, are possible, to form new variants or allotropes Bct, of silicon, semiconductors, which could then have some application in component electronics. Its basic properties will also be studied in nonlinear optics; trying to provide a complete study on these new allotropes, variants of Bct - C4.

Abstract: Total cross section for single electron-impact ionization of pyrimidine (C4H4N2), 2–chloropyrimidine (2-C4H3ClN2), 5–chloropyrimidine (5-C4H3ClN2), 2–bromopyrimidine (2-C4H3BrN2) and 5–bromopyrimidine (5-C4H3BrN2) molecules has been calculated with the binary-encounter-Bethe model from the ionization threshold up to 5 keV. The input data for the BEB calculations concerning electronic structure of the studied targets have been obtained with quantum chemical methods including the Hartree-Fock (H-F) and the outer valence Green function (OVGF) methods. The calculated cross section for ionization of pyrimidine molecule due to electron impact is compared with available experimental and theoretical data. The question of the magnitude the pyrimidine ionization cross section is also discussed. Efficiency of the ionization process of studied halogenated derivatives of pyrimidine is also discussed.

Abstract: Using the optical interaction potential between an electron and a helium atom, we calculate the collision frequency and energy transfer rate during the elastic scattering of electrons on helium atoms. The resulting effective frequency as a function of energy exhibits a maximum consistent with experimental data. The rate of energy transfer is in good agreement with other authors' calculations at low electron energies, with discrepancies increasing as the energy increases.

Abstract: The total and differential cross sections and final state distribution for mutual neutralization in collisions of Li+ with O− have been calculated using an ab initio quantum mechanical approach based on potential energy curves and non-adiabatic coupling elements computed with the multi-reference configuration interaction method. The final state distributions favor channels with excited oxygen states, indicating a strong effect of electron correlation, and the electron transfer cannot be described by a simple one-electron exchange process.

Abstract: In the context of the Bridge Electromagnetic Theory, a quantum-relativistic theory based on Maxwellian electromagnetism, it has recently been shown that the characteristics of a hydrogen atom can be obtained through an electron-proton orbital capture process forming a non-radial emitting dipolar electromagnetic source. The model structurally different to the Bohr-Sommerfeld and Schrödinger models has now been deepened and completed by testing it on the properties of hydrogen and deuterium atoms and of helium and lithium in hydrogenoid form. These last two atoms are of cosmological interest as they are the heaviest elements produced by electron capture in the early universe. The theoretical results obtained regarding the atomic structure and spectra are in excellent agreement with the observational data by suggesting the implicit correctness of the model. It is also highlighted that the electron-nucleus interaction is influenced on an isotopic basis as a function of the value of the inertial mass of the nuclei considered.

Abstract: The interaction of pulsed lasers with matter involving nanomaterials as a pure target or thin layer deposited on a target, initiates transient plasma which shows strong enhancement in a spectral line emission. This domain of research has been explored via two well established techniques dubbed NELIBS and NELIPS. These Nano-Enhanced Laser Induced Breakdown or Plasma Spectroscopy techniques entail similarities as well as differences. Thereupon, certain confusion has arisen from various aspects of the similarities as well as differences between the two techniques. In this article, we will investigate the application of either technique to retrieve relevant data about enhanced spectral line plasma emission phenomenon. To discriminate between these two techniques, survey on the nature of target, the origin of enhancement and prevalent theoretical approaches is presented. Finally, potential achievements, challenges, and the expected prospective are highlighted.

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Abstract: The effects of neighboring transitions (ENT) on electromagnetically induced transparency (EIT), electromagnetically induced absorption (EIA), and the conversion between EIA and EIT in a degenerate multi-level system of 87Rb atoms were studied in terms of the angle (θ) between the polarization axes of the coupling and probe beams. The predicted critical values of θ, in which EIT transitioned to EIA, were consistent with the experimental values. In this work these results were systematically confirmed using the calculated spectra by varying the frequency spacings in the excited state of 87Rb via a factor called the ratio. We observed that when the ratio was less than 0.1, the critical angle θc was inverted. This may be attributed to the interplay between the strengths of the EIA and EIT as the ENT varied. We also discovered that by modifying the frequency spacings in the excited state of 87Rb, it becomes feasible to predict ENT and the interplay between EIT and EIA in alkali-metal atoms.

Abstract: The central of this article is to present a hypothesis that can solve the long-standing question of how ball lightning arises.

Abstract: Quantum computing operates using qubits, the basic units of quantum information, which enable quantum algorithms to solve complex problems that classical computers cannot efficiently handle. This review provides a comparative analysis of several promising qubit technologies, including superconducting qubits, topological qubits, spin qubits, photonic qubits, ion trap qubits, and nitrogen-vacancy (NV) centers in diamonds. We discuss the operational principles, key researchers and institutions in each field, current advancements, challenges, and future directions for these technologies. This paper aims to present a thorough overview of the different approaches in qubit technologies and their potential impacts on quantum computing’s future landscape.

Abstract: It is argued that the compressibility of individual atoms is distinct from the compressibility of matter as a whole. The latter arises from variations in interatomic spacing, whereas the former is a purely quantum effect, characteristic of a given atomic species. Its magnitude can be deduced by solving the Schrödinger equation for an individual many-electron atom with modified external boundary conditions. Over a wide range of parameter space, quantum dilation or compression remains isoelectronic for neutral atoms but, at ultra-high pressures, reordering of their shell structure can occur. Their compression then ceases to be isoelectronic and their chemical properties, as well as their positioning in the Periodic Table, undergo sudden change.

Abstract: The study of the morphology, thermal, and chemical stability of the fluorinated compounds was performed using Becke’s three-parameter hybrid functional approach with the correlation provided by Lee, Yang, and Parr and the cc-pVTZ basis set aiming to design low sensitivity, toxicity, instability, and proneness to decomposition or degradation over a short time high-energy materials. The most stable conformers of the compounds under study were selected based on their total energy. Their thermal and chemical stability was evaluated based on the binding energy per atom, chemical hardness, and softness. The oxygen-fluorine balance is assessed to evaluate the sensitivity of these new materials. The density, detonation pressure, and velocity of the selected conformers were theoretically obtained to reveal the influence of -CF3, -OCF3, and cyclic -O(CF2)nO- fragments on the energetic properties of nitroaromatics as well as their stability and resistance to shock stimuli. The results allow us to predict new multipurpose energetic materials with a good balance between power and stability. Referring to the results obtained, we recommend CF3N2, OCF3N2, C2F6N2, 1CF2N2/O2CF2N2, and 2CF4N2/O2C2F4N2 for practical usage because these compounds possess greater stability compared to tetryl and better explosive properties than TNT.

Abstract: Recent progress in studies of Rydberg double-well electronic energy states of MeNg (Me=12-group atom, Ng=noble gas atom) van der Waals (vdW) molecules is presented and analysed. The presentation covers approaches in experimental studies as well as ab-initio-calculations of potential energy curves (PEC). The analysis is shown in a broader context of Rydberg states of hetero- and homo-diatomic molecules with PECs possessing complex ‘exotic’ structure. Laser induced fluorescence (LIF) excitation spectra and dispersed emission spectra employed in spectroscopical characterization of Rydberg states are presented on the background of diversity of spectroscopic methods of their investigations such as laser vaporization-optical resonance (LV-OR), pump-and-probe methods and polarization labelling spectroscopy. Importance and current state-of-the-art applications of Rydberg states with irregular potentials in photoassociation (PA), vibrational and rotational cooling, molecular clocks, frequency standards and molecular wave-packet interferometry is highlighted.

Abstract: We investigate solutions of the classical Mathieu-Hill (MH) equation which describes the dynamics of trapped ions, based on the Floquet theory and the analytical model introduced in \cite{Blu89}. We show the equations of motion are equivalent to those of the harmonic oscillator (HO) and demonstrate methods to determine the solutions of the MH equation. The regions of stability and instability for the MH equation in case of a trapped particle are also discussed. What is more, we address both the damped HO and parametric oscillator (PO) for an ion confined in a Paul trap. The paper is a follow-up of a recently published paper in Photonics, 11 (6) 551.

Abstract: Charge-dipole interactions are very common interactions among atoms and molecules, especially materials that can emit light or contain free charges. The second-order charge-dipole interactions, proportional to $\frac{1}{R^4}$, are stronger than the second-order dipole-dipole interactions or van der Waals interactions, proportional to $\frac{1}{R^6}$, at longer distances. In reality, there is more than one atom or charge; therefore, we focus on few-body charge-dipole interactions, such as charge-dipole-dipole interactions. Laser cooling and trapping allow us to study such interactions with much higher precision. In this article, charge-dipole interactions will be investigated in ultracold gases. To increase the interaction strength, we excite the ultracold atoms to highly excited states, Rydberg states. Here, we treat one Rydberg atom as a dipole, the excited electron and the ion core are the two poles of an electric dipole. Specifically, we study charge-atom interactions in ultracold Rydberg gases.