Electric Dipole Polarizability Research Articles

Polarizabilities from kaon Compton scattering

The polarizabilities of light pseudoscalar mesons can be extracted from differential cross sections for Compton scattering near threshold. While this has been accomplished for charged pions employing Primakoff reactions, a corresponding measurement for kaons will be affected by the presence of the K∗(892) resonance not too far from threshold. We propose a method to extend the energy range serviceable for this purpose by reconstructing the K∗(892) contribution model-independently from its Kπ intermediate state, using dispersion theory. We point out that, in contrast to the charged-pion analog, there is likely no strong hierarchy between sum and difference of electric and magnetic dipole polarizabilities; we discuss the sensitivity to disentangling both by improved experimental angular coverage.

Constraining Symmetry Energy from Pygmy Dipole Resonances in 68Ni and 132Sn

Abstract We make a new investigation on the correlation at saturation (subsaturation) density between the density dependence of symmetry energy and the percentage of energy-weighted sum rule (EWSR) exhausted by the pygmy dipole resonances (PDR) in $^{68}$Ni and $^{132}$Sn. The calculations are performed within Skyrme HF (or HF+BCS) plus random phase approximation (RPA) (or quasiparticle RPA) by using SAMi-J effective interactions. The effect of pairing on the dipole strength distribution of $^{68}$Ni and the density dependence of symmetry energy is discussed. The slope parameter L and symmetry energy J at saturation (subsaturation) density are 41.8-90.2 MeV (39.3-64.1 MeV) and 28.0-32.5 MeV (23.0-23.8 MeV). They are consistent with the currently accepted values except for the symmetry energy J at subsaturation density, it is slightly smaller than the data from nuclear mass differences and electric dipole polarizability.

Synthesis, Crystal Structure, Intermolecular Interactions, HOMO-LUMO, MEP, NLO Properties, and DFT/TD-DFT Investigation of (Z)-5-(4-Nitrobenzylidene)-3-N(3-Chlorophenyl)-2-Thioxothiazolidin-4-One

A novel heterocyclic compound named (Z)-5-(4-nitrobenzylidene)-3-N(3-chlorophenyl)-2-thioxothiazolidin-4-one (NCTh) was synthesized and analyzed using various techniques, including single crystal X-ray diffraction, FT-IR, UV-Vis, NMR spectroscopy, and mass spectral data methods. NCTh was observed to crystallize in the triclinic crystal system P-1 space group. To validate the experimental findings, density functional theory (DFT) calculations were performed using the B3LYP functional with the 6-311 G(d,p) basis set. The results indicated good agreement in geometrical parameters between the experimental and theoretical outcomes. The study also calculated HOMO-LUMO energies, molecular electrostatic potential (MEP), and global chemical reactivity descriptors to evaluate the compound’s reactivity. Additionally, the study conducted reduced density gradient and Hirshfeld surface analyses to reveal attractive, repulsive, and van der Waals strong and weak interactions. The calculation of thermodynamic parameters was also included. The study focused on investigating the nonlinear optical (NLO) properties of NCTh, which were characterized through key parameters such as the electric dipole moment (µ), polarizability (α), first-order hyperpolarizability (β), and second-order hyperpolarizability (γ). These properties provide insights into the material’s potential applications in optical and photonic technologies. Additionally, a molecular docking study was performed to further explore the structure-activity relationship, particularly in a biological context. The docking results revealed a strong ligand-protein interaction, with a binding energy of −10.3 kcal/mol, indicating significant affinity. Moreover, the inhibition constant (Ki) was calculated to be 0.0281 μM, suggesting a highly potent interaction, which could be relevant for drug design or biochemical applications.

Electric dipole polarizabilities and tune-out wavelengths for 23S1 and 33S1 states of Be2.

The electric dipole polarizabilities and the tune-out wavelengths for the n3S1 (n = 2, 3) states of Be2+ are determined through the application of the relativistic full-configuration-interaction approach. Our calculations directly integrate the mass shift operator into the Dirac-Coulomb-Breit Hamiltonian and further assess the quantum electrodynamics (QED) correction to the dynamic dipole polarizabilities using perturbation theory. The results reveal that the static electric dipole polarizability of the 23S1 and 33S1 states, as well as the 93nm tune-out wavelength of the 23S1 state and the 238nm tune-out wavelength of the 33S1 state, exhibits a high sensitivity to QED correction, which exceeds 80 ppm, providing a sensitive test for atomic structure theory.

Understanding the relationship between electric dipole polarizability and photonuclear (-2) moment in odd-A actinide nuclei

The nuclear electric dipole (E1) polarizability (α E1) is mainly dominated by the dynamics of the giant dipole resonance (GDR). α E1 is proportional to the (-2) moment of the total photo nuclear cross-section (σ −2). This research investigates the relationship between α E1 and σ −2, along with the effects of the Pygmy Dipole Resonance (PDR) and GDR in odd-mass actinide nuclei. For the first time, α E1 and σ −2 values have been calculated using the Translational and Galilean Invariant Quasiparticle Phonon Nuclear Model (TGI-QPNM) approach for odd-A actinide nuclei. According to TGI-QPNM results, E1 dipole transitions in the GDR region significantly contribute to σ −2 due to the energy weighting factor. Below the neutron separation threshold, the PDR in neutron-rich nuclei shows a contribution of about 5% to σ −2 values. In this region, E1 polarizability can reach values of 20%–25%. The α E1 values indicate the presence of PDR in these nuclei. Additionally, the Adaptive Neuro-Fuzzy Inference System (ANFIS), a new machine learning method, has been performed to analyze the relationship between α E1 and σ −2. The ANFIS results have been compared with those from the TGI-QPNM and experimental data. The TGI-QPNM model achieves an R2 of 0.85–0.95, while the ANFIS model achieves an R2 of 0.99. Moreover, the study suggests that the ANFIS model, consistent with TGI-QPNM results, could be an effective tool for estimating σ −2 in odd-A actinide nuclei.

Advantageous Effects of Phase Transition-Modulated Electric Polarization of Hollow CuSx for Enhanced Electromagnetic Wave Absorption.

Scrutinizing the electromagnetic wave absorption mechanism of sulfides remains a challenge due to the variability of the modulation of the crystal structure of the sulfides. To take advantage of this variability, nanosheet-assembled Cu9S5/CN composites with sulfur vacancies were prepared in this study by self-assembly synthesis and subsequent high-temperature heat treatment. Systematic studies show the phase transition-dependent induced decrease in the conductivity, the defect site-induced difference in the charge density, the weakened vacancy formation of defect polarization loss, and the influence of valence state on electric dipole polarization loss and interfacial polarization loss, making the optimization of the dielectric constant a significant positive effect on the improvement of impedance matching. This work provides a reliable example and theoretical guidance for the crystal structure design for the preparation of a new generation of efficient sulfide-based wave-absorbing materials.

Demonstration of a tunable interface between Rydberg atoms and superconducting microwave circuits with differential polarizability nulling

Microwave-dressed Rydberg atoms in pairs of states that are optically accessible and engineered so that the frequency of the transition between them is tunable while exhibiting a low sensitivity to stray electric fields have been interfaced with a superconducting coplanar waveguide (CPW) microwave resonator. This was achieved with helium atoms in triplet Rydberg states with principal quantum numbers n=55 and 56. The atoms were dressed with two strong microwave fields—a control field and a differential polarizability nulling field. The control field allowed the atoms to be coupled to the resonator using the two-color two-photon transition between the equal parity 1s55sS13≡|55s〉 and 1s56sS13≡|56s〉 Rydberg states, with one photon supplied by it and the other provided by the resonator. The nulling field was detuned from the field-free 1s55sS13→1s55pPJ3≡|55p〉 transition to admix |55p〉 character into the |55s〉 state and eliminate the differential static electric dipole polarizability of the |55s〉 and |56s〉 states. The experiments were performed with atoms located ∼300µm above a λ/4 niobium nitride superconducting CPW resonator operated at temperatures between 3.59 and 3.73K. The measured ac and dc Stark shifts of the Rydberg states at this atom-circuit interface in the presence of the dressing fields are in good quantitative agreement with the results of Floquet calculations. The differential polarizability nulling fields used in the experiments allowed the difference in the Stark shifts of the |55s〉 and |56s〉 states over the range of dc fields offset from the residual stray field by ±65 mV/cm to be reduced from 2π×2.1 MHz to 2π×125 kHz. Published by the American Physical Society 2024

Local charge regulation via selenium vacancies engineering in dielectric cobalt diselenide with enhanced microwave absorption

The weak electromagnetic loss capability of the single semiconductor material is difficult to meet the complicated electromagnetic environment nowadays, so vacancy engineering is employed to optimize the dielectric loss capability of CoSe2. Selenium vacancies are introduced into CoSe2 by re-annealing treatment, and the test results show that the selenium vacancies concentration enlarged with annealing temperature. The formation of selenium vacancies introduces a localized state in CoSe2, which enhances the capability of CoSe2 to trap charge carriers, and the increased conductivity contributes to the enhancement of the dielectric loss capability. Density Functional Theory (DFT) calculations demonstrate that the selenium vacancies disrupt the original charge equilibrium distribution of the CoSe2, and the non-recombined positive and negative charge centers induce a strong electric dipole polarization loss. Benefiting from the optimization of CoSe2 dielectric loss by the selenium vacancies engineering, RLmin of CoSe2-600 reaches −30.73 dB and the effective absorption bandwidth reaches 4.00 GHz at 1.8 mm. This study provides a simple and effective solution to optimize the microwave absorption performance of single-component microwave absorption materials.

Standard Response Calculation of Electric Dipole Polarizability and Specific Optical Rotation Power Densities.

A time-dependent method has been developed to solve the standard response equation for the calculation of dynamic molecular property densities, endowed with the characteristic of being origin-invariant, entirely in the atomic orbital basis at both HF and DFT level of theory. The method has been tuned in particular for the calculation of origin-independent electric dipole polarizability density and specific rotation power density. Some demonstrations are given for the hexabenzocoronene molecule and the Tröger's base.

Direct ab initio calculation of the 4He nuclear electric dipole polarizability

The calculation of nuclear electromagnetic sum rules by directly solving for numerous eigenstates in a large basis is numerically challenging and has not been performed for A>2 nuclei. With the significant progress of high performance computing, we show that calculating sum rules using numerous discretized continuum states obtained with the ab initio no-core shell model in the harmonic oscillator basis is achievable numerically. Specifically, we calculate the 4He electric dipole (E1) polarizability, that is an inverse energy weighted sum rule, employing the Daejeon16 NN interaction. We demonstrate that the calculations are numerically tractable as the dimension of the basis increases and are convergent. Our results for the 4He electric dipole polarizability are consistent with the most recent experimental data and are compared with those of other theoretical studies employing different techniques and various interactions.

Electric dipole polarizability of low-lying excited states in atomic nuclei

New equations for the electric dipole polarizability α E1 of low-lying excited states in atomic nuclei—and the related (−2) moment of the total photo-absorption cross section, σ −2—are inferred in terms of electric dipole and quadrupole matrix elements. These equations are valid for arbitrary angular momenta of the initial/ground and final/excited states and have been exploited in fully converged 1ℏ ω shell-model (SM) calculations of selected p- and sd-shell nuclei that consider configuration mixing; advancing previous knowledge from 17O to 36Ar, where thousands of electric dipole matrix elements are computed from isovector excitations which include the giant dipole resonance (GDR) region. Our results are in reasonable agreement with previous SM calculations and follow—except for 6,7Li and 17,18O—Migdal’s global trend provided by the combination of the hydrodynamic model and second-order non-degenerate perturbation theory. Discrepancies in 6,7Li and 17O arise as a result of the presence of α-cluster configurations in odd-mass nuclei, whereas the disagreement in 18O comes from the mixing of intruder states, which is lacking in the SM interactions. More advanced ab initio calculations of the dipole polarizability for low-lying excited states covering all the isovector states within the GDR region are missing and could be very valuable to benchmark the results presented here and shed further light on how atomic nuclei polarize away from the ground state

Orbital Hybridization Induced Dipole Polarization and Room Temperature Magnetism of Atomic Co‐N4‐C toward Electromagnetic Energy Attenuation

AbstractManipulating the electronic structure and geometric coordination environment of single metal atoms has been considered as promising approach for enhancing dipole polarization and enriching electromagnetic attenuation mechanisms. However, achieving precise control of the dielectric polarization response at atomic scale remains a huge challenge. Herein, a metal‐acetate coordination complexes‐assisted strategy is proposed to prepare spatially isolated cobalt (Co) atoms embedded in accordion‐like nitrogen‐doped carbon (NC) matrix. The interactions between metal atoms and NC matrix are carefully tailored through the successive evolution of dispersion states of Co species, ranging from individual atoms to atomic clusters to nanoparticles. Density functional theory reveals that the orbital hybridization between the d electrons of embedded Co atoms and p electrons of coordinated N atoms induces the electron redistribution at N sites, enabling enhanced electric dipole polarization and robust room temperature magnetism (a saturation magnetization of 0.108 emu g−1 at 300 K). Consequently, Co‐SAs@NC exhibits optimal electromagnetic wave absorption properties with a minimum reflection loss of ‐54.4 dB and an effective absorption bandwidth of 8.4 GHz. This work demonstrates an efficient strategy for modulating electromagnetic response at atomic level and provides a novel insight into the d/p electrons orbital hybridization between single metal atoms and NC species.

Electric dipole polarizability of magic nuclei

The correlations between the electric dipole polarizability and neutron skin thickness are studied by the magic nuclei 40,48Ca, 68,78Ni, 132Sn, and 208Pb. The strength distribution of the E1 transitions is calculated within the random phase approximation model based on the Skyrme nuclear energy density functional. A comparison with the experimental data has allowed us to constrain the value of the nuclear symmetry energy J = 30–37 MeV.

Synthesis, crystal structure, DFT calculations, NBO, Fukui function, NCI-RDG, Hirshfeld surface analysis, NLO properties and molecular docking analysis on (E)-N'-(3-methoxybenzylidene)-2-(quinolin-8-yloxy) acetohydrazide

In this study, we present the synthesis and characterization of a novel organic compound, (E)-N'-(3-methoxybenzylidene)-2-(quinolin-8-yloxy) acetohydrazide. Our characterization includes single crystal X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and UV–visible spectroscopy. We also conducted Hirshfeld surface (HS) analysis to investigate intermolecular interactions. The compound crystallizes in the triclinic system with space group P−1. We employed density functional theory (DFT) with the B3LYP function and the 6–311 G (d, p) basis set to calculate its electronic properties. Additionally, we explored its nonlinear optical (NLO) behavior, determining the electric dipole moment (μ), polarizability (α), and hyperpolarizability (β), second-order hyperpolarizabilities (γ) using the same basis set. To evaluate the NLO properties of MBQA, we conducted frontier molecular orbitals (FMO) analysis, examined HOMO-LUMO energies, determined the energy band gap, studied the density of states (DOS), and assessed global chemical reactivity descriptors. We also performed a molecular electrostatic potential (MEP) simulation to identify optimal sites for both electrophilic and nucleophilic attacks. Our analysis further included a reduced density gradient (RDG) analysis to investigate various types of intermolecular interactions in MBQA, such as repulsive, attractive, and Van der Waals interactions while also distinguishing between strong and weak interactions. To understand the molecular stability and interactions, we conducted natural bond orbital (NBO) analysis, which provided insights into hyperconjugative interactions, charge delocalization and electron density ED among the molecular components. Finally, we assessed the biological activity of the MBQA molecule by predicting its potential pharmacological activities using the prediction of activity spectra for substances (PASS) and conducting molecular docking analyses. This comprehensive study provides valuable insights into the structural, electronic, and biological properties of (E)-N'-(3-methoxybenzylidene)-2-(quinolin-8-yloxy) acetohydrazide (MBQA).

CNTs-improved electromagnetic wave absorption performance of Sr-doped Fe3O4/CNTs nanocomposites and physical mechanism

Electromagnetic wave pollution is a serious environmental problem, and it is urgent to develop high-efficiency electromagnetic wave absorption (EMA) materials. In this paper, carbon nanotubes (CNTs) were combined with Sr-doped Fe3O4 nanoparticles to form Sr-doped Fe3O4/CNTs nanocomposites with by hydrothermal method. After the characterization of microstructure and magnetic properties, EMA properties of Sr-doped Fe3O4/CNTs nanocomposites are investigated in detail. The well-dispersed CNTs lead to the uneven average grain size of Sr-doped Fe3O4 nanoparticles and a little decrease of saturation magnetization. While CNTs greatly improve EMA performance, and SFC1 sample exhibits the minimum reflection loss value of −65.64 dB at 6.32 GHz with the thickness of 3 mm. CNTs reduces the natural resonance of magnetic loss while increasing the permittivity, conductivity, and heterogeneous interfaces. As the result, Sr-doped Fe3O4/CNTs nanocomposites exhibit not only better impedance matching but also higher electric dipole polarization relaxation loss, interfacial relaxation loss, conductivity loss, and eddy current loss. In this way, the excellent EMA performance is attributed to the good impedance matching, intense dielectric loss and enhanced eddy current loss for Sr-doped Fe3O4/CNTs nanocomposites.

Global trends of the electric dipole polarizability from shell-model calculations

Global trends of the electric dipole polarizability from shell-model calculations

Ab initio interaction potentials of alkali metal (M = Na and K)–rare gas (Rg = He, Ne, Ar, Kr, Xe and Rn) complexes

Spectroscopic properties and potential energy curves of alkali metal (M = Na and K) – rare gas (Rg = He, Ne, Ar, Kr, Xe and Rn) van der Waals molecules in their ground states have been studied in detail using spin-restricted open-shell coupled cluster with single and double excitations and perturbative contribution of connected triple excitations (RCCSD(T)) methods. The core-valence correlation (CV) effect was found to be crucial for M-RG molecules containing heavy rare gas atoms. The electronic energies were corrected for the basis set superposition error (BSSE) using the counterpoise method. Energies were extrapolated to the complete basis set (CBS) limit using a two-point scheme. The permanent electric dipole moments, static electric dipole polarizabilities and long-range dispersion coefficients were also calculated. The computed spectroscopic constants, vibrational levels and rotational constants were reported for M-RG and good agreement with the available experimental and theoretical values were found.

Origin-Independent Dynamic Polarizability Density from Coupled Cluster Response Theory.

The calculation of the origin-independent density of the dynamic electric dipole polarizability, previously presented for uncorrelated and density functional theory (DFT)-based methods, has been developed and implemented at the coupled cluster singles and doubles (CCSD) level of theory. A pointwise analysis of polarizability densities calculated for a number of molecules at Hartree-Fock (HF) and CCSD clearly shows that the electron correlation effect is much larger than one would argue considering the integrated dipole electric polarizability alone. Large error compensations occur during the integration process, which hide fairly large deviations mainly located in the internuclear regions. The same is observed when calculated CCSD and B3LYP polarizability densities are compared, with the remarkable feature that positive/negative deviations between CCSD and HF reverse sign, becoming negative/positive when comparing CCSD to B3LYP.

Reduced Radial Curves of Diatomic Molecules.

The prospect of using the concept of a universal reduced potential energy curve (RPC) for a broader class of radial molecular functions is explored by performing appropriate model calculations for the electric dipole moment functions of the hydrogen halides HF, HCl, and HBr. The reduced radial functions of the model systems, constructed from their best available theoretical approximants, coincide so closely that they can be used as few-parameter universal representations of functions available in the literature. Given the mathematical nature of the problem addressed here, the results are not limited to the functions studied but can be applied equally well to all radial molecular functions that have similar shapes, such as electric quadrupole moment and dipole polarizability functions.

Tunable Rydberg–Rydberg transitions in helium with reduced sensitivity to dc electric fields by two-colour microwave dressing

The difference in the static electric dipole polarizabilities of the and Rydberg levels in helium has been eliminated by dressing the atom with a microwave field near resonant with the single-photon transition. For an amplitude dressing field, detuned by from the zero-field transition frequency, the dc Stark shift of the two-photon transition between these states remained within for electric fields up to . This transition was probed by single-color two-photon microwave spectroscopy, and by two-color two-photon spectroscopy with one strong additional dressing field and a weak probe field. For all measurements, the transition frequencies and Stark shifts were compared, and found to be in excellent quantitative agreement with the results of Floquet calculations of the energy-level structure of the Rydberg states in the presence of the dressing fields and applied dc electric fields. The two-color microwave dressing scheme demonstrated, with one field applied to null the differential polarizability of the Rydberg–Rydberg transition, and the second exploited to allow the two-photon transition to be employed to achieve tunable absorption of single-photons from a weak probe field, will facilitate improved coherence times and tunable single-photon absorption in hybrid cavity QED experiments with Rydberg atoms and superconducting microwave circuits.