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Self-propelled particles possessing permanent magnetic dipole moments occur naturally in magnetotactic bacteria and can be built into man-made systems such as active colloids or micro-robots. Yet, the interplay between self-propulsion and anisotropic dipole–dipole interactions on dynamic self-assembly in three dimensions (3D) remains poorly understood. We conduct Brownian dynamics simulations of active dipolar particles in 3D, focusing on the low-density regime, where dipolar hard spheres tend to form chain-like aggregates and percolated networks with increasing dipolar coupling strength. We find that strong active forces override dipolar attractions, effectively inhibiting chain-like aggregation and network formation. Conversely, activating particles with low to moderate forces results in a fluid composed of active chains and rings. At strong dipolar coupling strengths, this active fluid transitions into an active gel, consisting of a percolated network of active chains. Although the overall structure of the active gel remains interconnected, the network experiences more frequent configurational rearrangements due to the reduced bond lifetime of active dipolar particles. Consequently, particles exhibit enhanced translational and rotational diffusion within the active fluid of strings and active gels compared to their passive counterparts. We quantify the influence of activity on aggregate topology as they transition from branched structures to unconnected chains and rings. Our findings are summarized in a state diagram, delineating the impact of dipolar coupling strength and active force magnitude on the system. [ABSTRACT FROM AUTHOR]

A deterministic, bright, room-temperature stable single-photon source (SPS) has been a major demand in the field of quantum photonics. Here, using computational and analytical techniques, we showed that the Mie-scattering moments of an all-dielectric cavity-cum-antenna help in shaping the spontaneous emission process of an embedded point-dipole emitter, the nanodiamond-based NV − and SiV color centers here. Our resonator-cum-antenna design comprises two top and bottom TiO 2 cylinders with a sandwiched polyvinyl alcohol (PVA) layer enclosing the nanodiamond crystal. The Cartesian multi-polar decomposition of the Mie-scattering moments of the sandwiched PVA layer (enclosing the dipole emitter) with subwavelength scale thickness showed strong electric-dipole (ED) resonance. This resulted in significant field confinement, making the PVA layer to act as a cavity, providing a Purcell enhancement of more than an order of magnitude for all dipole orientations. The top and bottom TiO 2 cylinders were observed to act as an antenna, and the far-field radiation pattern of the embedded dipole-emitter is controlled by the Mie-scattering moments of the TiO 2 cylinders. The radiation directionality along the vertical directions was found to be maximum at the Kerker point (electric dipole moment, ED = magnetic dipole moment), the collection efficiency (CE) being about 80%. For dipole emission coupled to the antenna, the quantum efficiency was observed to increase to a high value of 0.98 for nanodiamond NV − center, very close to an ideal case of purely radiative emission. Our scheme is shown to be universal and can be applied to any solid-state-based quantum emitters, for generating on-demand SPS for quantum-photonic applications. [ABSTRACT FROM AUTHOR]

Comprehensive spectrotemporal analyses of the Z-type neutron star low-mass X-ray binary GX 5−1 were performed using 10 broad-band observations from AstroSat /Soft X-ray Telescope and Large Area X-ray Proportional Counter (LAXPC) instruments. The LAXPC-20 hardness–intensity diagram showed horizontal and normal branches (HBs and NBs) of the Z track which exhibited secular motion. The time-averaged spectra in the energy range 0.7–25.0 keV could be fitted with the model combination – |$\tt {constant}\, \times \, \tt {tbabs}\, \times \, \tt {edge}\, \times \, \tt {edge}\, \times \, \tt {thcomp}\, \times \, \tt {diskbb}$|⁠. This yielded |$\Gamma \, \sim$| 2, |$kT_{\mathrm{ e}}\, \sim$| 3.3 keV, and |$F_{\mathrm{ disc}}$| / |$F_{\mathrm{ total}}\, \sim$| 0.8 indicating the soft/intermediate spectral state of the source during the observations. Flux-resolved spectral analysis revealed a positive correlation between |$kT_{\mathrm{ in}}$| and |$F_{\mathrm{ bol}}$|⁠. However, a negative correlation was observed between them in one of the NBs. Time-averaged temporal analysis revealed multiple HB oscillations (HBOs) and NB oscillations (NBOs), and peaked noise components in the |$\sim$| 5–50 Hz range. Furthermore, flux-resolved temporal analysis showed that the frequency of the HBOs correlates positively whereas the strength of HBOs correlates negatively with |$F_{\mathrm{ bol}}$|⁠ , indicating their probable origin from the accretion disc. In contrast, the frequency and strength of NBOs remain fairly constant with |$F_{\mathrm{ bol}}$|⁠ , suggesting that they originate from a different region in the system. Using the relativistic precession model along with highest frequency of the HBO, the upper limits of the magnetic dipole moment (⁠|$\mu$|⁠) and field strength (B) at the poles of the neutron star in the system were found to be 25.60 |$\times \, 10^{25}$| G cm3 and 3.64 |$\times \, 10^{8}$| G, respectively, for |$k_{\mathrm{ A}}$| = 1. [ABSTRACT FROM AUTHOR]

The magnetic toroidal dipole moment, which is induced by a vortex-type spin texture, manifests itself in parity-breaking physical phenomena, such as a linear magnetoelectric effect and nonreciprocal transport. We elucidate that a staggered alignment of the magnetic toroidal dipole can give rise to spontaneous magnetization even under antiferromagnetic structures. We demonstrate the emergence of uniform magnetization by considering the collinear antiferromagnetic structure with the staggered magnetic toroidal dipole moment on a bilayer zigzag chain. Based on the model calculations, we show that the interplay between the collinear antiferromagnetic mean field and relativistic spin-orbit coupling plays an important role in inducing the magnetization. [ABSTRACT FROM AUTHOR]

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Chiral perovskites are considered as promising candidates for circularly polarized luminescence (CPL) light source, by attracting the broader scientific community for their applications in chiral optoelectronics and spintronics. However, it is still a great challenge to achieve both substantial photoluminescence asymmetry (gCPL) and high photoluminescence quantum yield (PLQY) simultaneously for high CPL brightness due to the limitations associated with magnetic transition dipole moments. Herein, this problem is overcome and achieve both large gCPL of 1.6×10−2 and PLQY of 56% in chiral perovskite through the magnetic element doping strategy. The substitution of Pb2+ ion with smaller magnetic Mn2+ ions shrinks the crystal lattice around [MnBr6]4− octahedra, amplifying the asymmetric distortion surrounding the Mn2+ ions. Moreover, the transition associated with Mn2+ ions can harvest the photoexcitation energy in chiral perovskites, and its spin‐flipping characteristics enable highly efficient CPL from the d–d transition on Mn2+ energy levels. Furthermore, this magnetic element doping strategy is proven to be a universal tactic for enhancing CPL brightness as confirmed in a series of 1D‐ or 2D‐chiral perovskites with various chiral ligands or halogens. The findings provide an in‐depth understanding of the structure‐property relationship in chiral perovskites toward chiral optoelectronic and spintronic applications. [ABSTRACT FROM AUTHOR]

Models of the resolved Event Horizon Telescope (EHT) sources Sgr A* and M87* are constrained by observations at multiple wavelengths, resolutions, polarizations, and time cadences. In this paper, we compare unresolved circular polarization (CP) measurements to a library of models, where each model is characterized by a distribution of CP over time. In the library, we vary the spin of the black hole, the magnetic field strength at the horizon (i.e., both SANE and magnetically arrested disk or MAD models), the observer inclination, a parameter for the maximum ion–electron temperature ratio assuming a thermal plasma, and the direction of the magnetic field dipole moment. We find that Atacama Large Millimeter/submillimeter Array (ALMA) observations of Sgr A* are inconsistent with all edge-on (i = 90°) models. Restricting attention to the MAD models favored by earlier EHT studies of Sgr A*, we find that only models with magnetic dipole moment pointing away from the observer are consistent with ALMA data. We also note that in 26 of the 27 passing MAD models, the accretion flow rotates clockwise on the sky. We provide a table of the means and standard deviations of the CP distributions for all model parameters, along with their trends. [ABSTRACT FROM AUTHOR]

The rotational bands of 55 Cr are studied with deformed Hartree–Fock (HF) and angular momentum projection techniques. Energy spectra are calculated up to high spin values J = 37 / 2 + . Configuration mixing is performed between different rotational aligned (RAL) bands and the band-mixed result is compared with the experimental bands. One-, three- and five-quasiparticle bands are studied here. Except these, we also predict some structural properties like magnetic dipole moment (μ ), static quadrupole moment ( Q 0 ) and spectroscopic quadrupole moment ( Q s ) along with deformation parameter for future verification. We used our microscopic model to predict band structures in the high K region too. Reduced transition probabilities, i.e. B(E2) and B(M1) values are calculated for all bands. Signature effect has been observed in low K spectra as well as in reduced transition probabilities. [ABSTRACT FROM AUTHOR]

This document explores the experimental and theoretical aspects of a magnetically coupled oscillator system with two swinging magnets. The setup is designed to allow for long-lasting oscillations and is cost-effective by utilizing a smartphone magnetometer to measure the dipole moment of the magnet and record the period of the oscillations. The document discusses various setups and approaches used in studying magnetically coupled oscillators, and presents a simplified setup that uses a low-friction pivot and a smartphone for data recording. The physical setup, theoretical model, and experimental results are described in detail. The document concludes by suggesting that this setup can be a valuable addition to existing experiments on coupled oscillators. [Extracted from the article]

We implement a distributed Bragg reflector (DBR) laser diode (LD) package with low-magnetic field generation. The package consists of a commercial 795 nm DBR LD chip, a thermo-electric cooler (TEC), a thermistor, a flexible printed circuit board (FPCB) which cancels the magnetic field emitted by the TEC current flow, and a non-magnetic aluminum case. We confirm that the magnetic dipole moment of our low-magnetic package body is about three orders of magnitude smaller than that of a commercial DBR laser package. Moreover, it is shown that our compensating FPCB, the effectiveness of which is supported by computer simulations, reduces the magnetic field magnitude by a factor of 2.2. The FPCB also reduces the magnetic field gradient emitted by the TEC current flow so that gradient-induced spin relaxations are suppressed in applications. A portable optically pumped atomic magnetometer (OPAM) utilizing two low-magnetic packages as light sources is reported as an application of the package and shows a 0.30 pT/Hz1/2 level magnetic sensitivity at a 69 μT external magnetic field; in contrast, the OPAM utilizing the commercial packages showed a magnetic sensitivity of 0.87 pT/Hz1/2. [ABSTRACT FROM AUTHOR]

Radiation energy scattered by a small particle can be expected to travel from the particle to a detector in the far field along the field lines of the Poynting vector. We consider the scattering off a small conducting sphere, for which only the induced electric and magnetic dipole moments contribute to the emitted radiation. Field lines of the energy flow due to interference between fields radiated by the electric and magnetic dipoles appear to form closed loops in the vicinity of the particle. Energy flows out of the particle at one side and then returns to the particle at the other side, and as such, this energy flow does not contribute to the radiated power. At larger distances, energy flows away from the particle at one side of the particle, but on the other side, radiation flows from infinity toward the particle. The energy for the scattered radiation is provided by the incident field. The energy flow is due to interference between the incident field and the scattered radiation, known as extinction. The flow pattern of this energy exhibits numerous singularities and vortices, and closed-loop flows near the particle. In the far field, energy flows along counter-oriented field line bundles, with only the net power flowing inward. [ABSTRACT FROM AUTHOR]

Many accretion-powered pulsars rotate in magnetocentrifugal disequilibrium, spinning up or down secularly over multiyear intervals. The magnetic dipole moment μ of such systems cannot be inferred uniquely from the time-averaged aperiodic X-ray flux 〈 L (t)〉 and pulse period 〈 P (t)〉, because the radiative efficiency of the accretion is unknown and degenerate with the mass accretion rate. Here, we circumvent the degeneracy by tracking the fluctuations in the unaveraged time series L (t) and P (t) using an unscented Kalman filter, whereupon μ can be estimated uniquely, up to the uncertainties in the mass, radius, and distance of the star. The analysis is performed on Rossi X-ray Timing Explorer observations for 24 X-ray transients in the Small Magellanic Cloud, which have been monitored regularly for ∼16 yr. As well as independent estimates of μ, the analysis yields time-resolved histories of the mass accretion rate and the Maxwell stress at the disk–magnetosphere boundary for each star, and hence auto- and cross-correlations involving the latter two state variables. The inferred fluctuation statistics convey important information about the complex accretion physics at the disk–magnetosphere boundary. [ABSTRACT FROM AUTHOR]

Extremely/super low frequency (ELF/SLF) electromagnetic (EM) waves offer efficient propagation in challenging cross‐medium environments. However, conventional coil antennas, when emitting ELF/SLF EM waves, face constraints related to size, radiation efficiency, and high power consumption. To overcome these limitations, a disc‐rod structured piezoelectric rotating resonator is proposed, which can turn a NdFeB permanent magnet disc into rotation with an impressive high‐speed up to 10 000 r min−1 via wobbling motion of the rod tip, effectively generating ELF/SLF magnetic field radiation via rotational oscillation other than common linear and swinging oscillation of the magnetic dipole moments. The piezo‐turned magnetic rotation (PTMR) method leads to a two to five‐fold enhancement in magnetic field emission compared to existing piezo‐actuated acoustic resonant antennas, and a 370 times higher emitting efficiency compared to the traditional coil antenna with a comparable size. In contrast to unidirectional EM wave radiation at their solely resonant frequencies, the PTMR antenna showcases omnidirectional B‐field radiation with continuous tunability in a dual frequency band spanning from 10 to 100 Hz. Moreover, an air–seawater cross‐medium magnetic field communication is successfully demonstrated. With outstanding performance metrics, the PTMR antenna emerges as a promising solution for efficient long‐distance ELF/SLF cross‐medium communication. [ABSTRACT FROM AUTHOR]

The spectral properties of the transient neutron star low-mass X-ray binary XTE J1701−462 were studied using the data obtained from FPMA/B detectors onboard NuSTAR during its second known outburst (2022 September). The physical parameters of the system were derived from the analysis of the data in the 3.0−30.0 keV energy range. The patterns displayed on the hardness–intensity diagram of the three observations closely resembled the banana branch/normal branch, a vertex of horizontal and normal branch of the Z-track and a transition from normal branch to flaring branch. Spectral analysis of the source revealed the presence of Fe K emission complex. The source spectra were fitted with a multitemperature blackbody (⁠|$\tt {diskbb}$|⁠) component in conjunction with the reflection model (⁠|$\tt {relxillNS}$|⁠). The values of temperature (kT in) and radius (R in) of the inner accretion disc obtained from the spectral fitting with the model combination – |$\tt {constant} \times \tt {tbabs} (\tt {diskbb}$|  +  |$\tt {relxillNS})$| showed the source to be in its soft spectral state during the observations. The inclination angle (θ) of the source was estimated to be between 19° and 33° and the inner disc radius (R in) was found to be 17.4 km. Assuming the case of magnetic truncation of accretion disc, the upper limits for the magnetic dipole moment (μ) and the magnetic field strength (B) at the poles of the neutron star in the system were found to be 5.78 × 1026 G cm3 and 8.23 × 108 G, respectively, for kA  = 1. [ABSTRACT FROM AUTHOR]

The origin of nuclear magnetic shielding in diamagnetic molecules is discussed, pointing out various contributions to the shielding from electrons and the effects of intra- and intermolecular interactions. In NMR practice, chemical shifts are determined first as the measure of shielding in observed samples. The descriptions of shielding and chemical shifts are not fully consistent. Gas phase studies permit the withdrawal of intermolecular contributions from shielding and obtaining the magnetic shielding data in isolated molecules. The shielding determination in molecules is possible using at least three methods delivering the reference shielding standards for selected nuclei. The known shielding of one magnetic nucleus can be transferred to other nuclei if the appropriate nuclear magnetic moments are available with satisfactory accuracy. It is possible to determine the nuclear magnetic dipole moments using the most advanced ab initio shielding calculations jointly with the NMR frequencies measurements for small-sized isolated molecules. Helium-3 gas is postulated as all the molecules' primary and universal reference standard of shielding. It can be easily applied using common deuterium lock solvents as the secondary reference standards. The measurements of absolute shielding are available for everyone with the use of standard NMR spectrometers. [ABSTRACT FROM AUTHOR]

In Frenkel model of charged particle possessing magnetic moment the magnetic dipole interaction with external field manifests itself not only in Stern–Gerlach (SG) force but in particle's inertia as well. Within this model there exists general procedure to obtain spin corrections to the system of Lorentz and BMT equations which here is applied to the event of the constant field and ( for protons). We obtain the reduced system of Frenkel equations for the trajectory and spin which guarantees the constraint and differs from Lorentz–BMT system by the non-linear spin corrections. The relative magnitude of these corrections is about ( being the magnetic moment energy in the rest frame (RF) of the particle) and is, generally, comparable in magnitude with the effects of non-homogeneity. The influence of non-linear spin corrections on the trajectory and spin evolution is examplified through the consideration of the proton moving in homogeneous magnetic field. [ABSTRACT FROM AUTHOR]

The dynamo actions of an electrically conducting fluid in a precessing sphere are investigated over a wide range of parameters by direct numerical simulation using a Galerkin spectral method. The focus of this work is to identify the most promising parameter regimes for the dynamo action and to investigate the characteristics of the magnetic field generated by precession. The influence of different nutation angles (30 ° , 60 ° , 90 °) and different precession ratios on the ability to drive dynamo action are investigated. The optimal angle for dynamo actions is found at 90 ° , followed by 60 ° with retrograde precession. A moderate precession ratio around 0.3 is shown to be more feasible for dynamo actions. A rich set of self-sustained dynamo solutions are obtained in the parameter space we explored, including steady, periodic, quasi-periodic, and turbulent dynamos. The structure of the generated magnetic fields is analyzed by using helical wave decomposition. None of the precession driven dynamos we obtained produce a predominantly dipolar field, contrary to the convection driven dynamos. The long-time evolution of the magnetic dipole moment is investigated and different types of polarity reversals are observed. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) chiroptical response has been less explored because it is challenging to achieve both chirality and NIR absorption/emission. Herein, we describe the design of heterohelicene‐type β‐isoindigo‐based boron‐dipyrromethene (BODIPY) analogs (β‐IBs), which shift the absorption peak to 800 nm and produce significant Cotton effects (127.8 M−1 cm−1) and absorbance dissymmetry factors (|gabs| = 3.5 × 10−3). The luminescence dissymmetry factor (glum) and circularly polarized luminescence (CPL) brightness (BCPL) of up to 1.24 × 10−3 and 1.78 M−1 cm−1 were realized beyond 800 nm. These β‐IBs are the first examples of helicene‐type compounds with the highest gabs in the NIR region and CPL beyond 800 nm. Theoretical calculations demonstrate that the strong chiroptical activities are triggered by their large transition magnetic dipole moments. This study not only provides a new approach to the synthesis of a larger variety of unprecedented helicene‐type BODIPY analogs but also demonstrates excellent NIR chiroptical properties. [ABSTRACT FROM AUTHOR]

To evaluate the long-distance magnetic field generated by neurons, we propose a reformulation of the brain's magneto-quasistatic approximation based on the Jefimenko's time-dependent generalization of the Biot–Savart law. This differs from the traditional approach relying on Maxwell's equations and not on their general solution. Instead of a typical length of the medium in the conventional approach, we use the signal traveling distance | r − r ′ ¯ | , from the farthest source point r ′ ¯ to the field point r , as the proper length to define the quasistatic dynamics. We consider relatively low frequencies below a typical value f max = 100 Hz. The quasistatic approximation is justified since (2 π f max) 2 | r − r ′ ¯ | 2 ϵ μ 0 ≈ 4 × 10 − 7 ≪ 1. We take | r − r ′ ¯ | ≈ 0.1 m , with the gray matter permittivity, previously underestimated, to be ϵ ≈ 10 7 ϵ 0. A formalism for the long-distance magnetic field generated by neuronal populations is then developed. Each population is described as a region of small dimensions compared to the average distance from the field point. We split the impressed current density into synaptic and action potential contributions and study their magnetic field. Assuming a small contribution of the impressed currents at the region boundary surface, we obtain two equivalent expressions of the synaptic current dipole moment in terms of the scalar potential and/or its spatial derivatives. Using Maxwell–Wagner's time, the synaptic current dipole moment of a region is also shown to be related to the electric dipole moment of each part with uniform conductivity and permittivity. Finally, the long-distance magnetic field of action potential currents is expressed in terms of the magnetic dipole moment for these currents. [ABSTRACT FROM AUTHOR]

Generating circularly polarized luminescence (CPL) with simultaneous high photoluminescence quantum yield (PLQY) and dissymmetry factor (glum) is difficult due to usually unmatched electric transition dipole moment (μ) and magnetic transition dipole moment (m) of materials. Herein we tackle this issue by playing a "cascade cationic insertion" trick to achieve strong CPL (with PLQY of ~100 %) in lead‐free metal halides with high glum values reaching −2.3×10−2 without using any chiral inducers. Achiral solvents of hydrochloric acid (HCl) and N, N‐dimethylformamide (DMF) infiltrate the crystal lattice via asymmetric hydrogen bonding, distorting the perovskite structure to induce the "intrinsic" chirality. Surprisingly, additional insertion of Cs+ cation to substitute partial (CH3)2NH2+ transforms the chiral space group to achiral but the crystal maintains chiroptical activity. Further doping of Sb3+ stimulates strong photoluminescence as a result of self‐trapped excitons (STEs) formation without disturbing the crystal framework. The chiral perovskites of indium‐antimony chlorides embedded on LEDs chips demonstrate promising potential as CPL emitters. Our work presents rare cases of chiroptical activity of highly luminescent perovskites from only achiral building blocks via spontaneous resolution as a result of symmetry breaking. [ABSTRACT FROM AUTHOR]

Helical nanographenes with high quantum yields and strong chiroptical responses are pivotal for developing circularly polarized luminescence (CPL) materials. Here, we present the successful synthesis of novel π‐extended double [7]helicenes (ED7Hs) where two helicene units are fused at the meta‐ or para‐position of the middle benzene ring, respectively, as the structural isomers of the reported ortho‐fused ED7H. The structural geometry of these ED7Hs is clearly characterized by single‐crystal X‐ray analysis. Notably, this class of ED7Hs exhibits bright luminescence with high quantum yields exceeding 40 %. Through geometric regulation of two embedded [7]helicene units from ortho‐, meta‐ to para‐position, these ED7Hs display exceptional amplification in chiroptical responses. This enhancement is evident in a remarkable approximate fivefold increase in the absorbance and luminescence dissymmetry factors (gabs and glum), respectively, along with a boosted CPL brightness up to 176 M−1 cm−1, surpassing the performance of most helicene‐based chiral NGs. Furthermore, DFT calculations elucidate that the geometric adjustment of two [7]helicene units allows the precise alignment of electric and magnetic transition dipole moments, leading to the observed enhancement of their chiroptical responses. This study offers an effective strategy for magnifying the CPL performance in chiral NGs, promoting their expanded application as CPL emitters. [ABSTRACT FROM AUTHOR]

This study explores the quantum size effects on the optical properties of pillar[n]arene (n = 5, 6, 7, 8) utilizing density functional theory (DFT) and wave function analysis. The mechanisms of electron transitions in one-photon absorption (OPA) and two-photon absorption (TPA) spectra are investigated, alongside the calculation of electron circular dichroism (ECD) for these systems. Transition Density Matrix (TDM) and electron–hole pair density maps are employed to study the electron excitation characteristics, unveiling a notable size dependency. Analysis of the transition electric dipole moment (TEDM) and the transition magnetic dipole moment (TMDM) reveals the electromagnetic interaction mechanism within pillar[n]arene. Raman spectra computations further elucidate vibrational modes, while interactions with external environments are studied using electrostatic potential (ESP) analysis, and electron delocalization is assessed under an external magnetic field, providing insights into the magnetically induced current phenomena within these supramolecular structures. The thermal stability of pillar[n]arene was investigated by ab initio molecular dynamics (AIMD). [ABSTRACT FROM AUTHOR]

The magnetic dipole moment μ of an accretion-powered pulsar in magnetocentrifugal equilibrium cannot be inferred uniquely from time-averaged pulse period and aperiodic X-ray flux data, because the radiative efficiency η 0 of the accretion is unknown, as are the mass, radius, and distance of the star. The degeneracy associated with the radiative efficiency is circumvented if fluctuations of the pulse period and aperiodic X-ray flux are tracked with a Kalman filter, whereupon μ can be measured uniquely up to the uncertainties in the mass, radius, and distance. Here, the Kalman filter analysis is demonstrated successfully in practice for the first time on Rossi X-ray Timing Explorer observations of the X-ray transient SXP 18.3 in the Small Magellanic Cloud (SMC), which is monitored regularly. The analysis yields μ = 8.0 − 1.2 + 1.3 × 10 30 G cm 3 and η 0 = 0.04 − 0.01 + 0.02 , compared to μ = 5.0 − 1.0 + 1.0 × 10 30 G cm 3 as inferred traditionally from time-averaged data assuming η 0 = 1. The analysis also yields time-resolved estimates of two hidden state variables, the mass accretion rate and the Maxwell stress at the disk–magnetosphere boundary. The success of the demonstration confirms that the Kalman filter analysis can be applied in the future to study the magnetic moments and disk–magnetosphere physics of accretion-powered pulsar populations in the SMC and elsewhere. [ABSTRACT FROM AUTHOR]

To achieve optoelectronic devices with high resolution and efficiency, there is a pressing need for optical structural units that possess an ultrasmall footprint yet exhibit strong controllability in both the frequency and spatial domains. For dielectric nanoparticles, the overlap of electric and magnetic dipole moments can scatter light completely forward or backward, which is called Kerker theory. This effect can expand to any multipoles and any directions, re‐named as generalized Kerker effect, and realize controllable light manipulation at full space and full spectrum using well‐designed dielectric structures. However, the complex situations of multipole couplings make it difficult to achieve structural design. Here, generative artificial intelligence (AI) is utilized to facilitate multi‐objective‐oriented structural design, wherein the study leverages the concept of "combined spectra" that consider both spectra and direction ratios as labels. The proposed generative adversarial network (GAN) is named as DDGAN (double‐discriminator GAN) that discriminates both images and spectral labels. Using trained networks, the simultaneous design for scattering color and directivities, RGB color routers, as well as narrowband light routers is achieved. Notably, all generated structures possess a footprint <600 × 600 nm indicating their potential applications in optoelectronic devices with ultrahigh resolution. [ABSTRACT FROM AUTHOR]

Change of conformation or polarization of molecules is an expression of their functionality. If the two correlate, electric fields can change the conformation. In the case of endofullerene single-molecule magnets the conformation is linked to an electric and a magnetic dipole moment, and therefore magnetoelectric effects are envisoned. The interface system of one monolayer Sc2TbN@C80 on hexagonal boron nitride (h-BN) on Ni(111) has been studied. The molecular layer is hexagonally close packedbut incommensurate. With photoemission the polarization and the conformation of the molecules are addressed by the work function and angular intensity distributions. Valence band photoemission (ARPES) shows a temperature-induced energy shift of the C80 molecular orbitals that is parallel to a change in work function of 0.25 eV without charging the molecules. ARPES indicates a modification in molecular conformations between 30 and 300 K. This order–disorder transition involves a polarization change in the interface and is centered at 125 K as observed with high-resolution X-ray photoelectron spectroscopy (XPS). The temperature dependence is described with a thermodynamic model that accounts for disordering with an excitation energy of 74 meV into a high entropy ensemble. All experimental results are supported by density functional theory (DFT). [ABSTRACT FROM AUTHOR]

Based on density functional theory (DFT) and wave function analysis, the ultraviolet and visible spectrophotometry (UV-Vis) spectra and Raman spectra of 1-meso and 1-rac obtained by the chiral separation of chiral nanographenes are theoretically investigated. The electron excitation properties of 1-meso and 1-rac are studied by means of transition density matrix (TDM) and charge density difference (CDD) diagrams. The intermolecular interaction is discussed based on an independent gradient model based on Hirshfeld partition (IGMH). The interaction of 1-meso and 1-rac with the external environment is studied using the electrostatic potential (ESP), and the electron delocalization degree of 1-meso and 1-rac is studied based on the magnetically induced current under the external magnetic field. Through the chiral separation of 1-rac, two enantiomers, 1-(P, P) and 1-(M, M), were obtained. The electrical–magnetic interaction of the molecule is revealed by analyzing the electron circular dichroism (ECD) spectra of 1-meso, 1-(P, P) and 1-(M, M), the transition electric dipole moment (TEDM) and the transition magnetic dipole moment (TMDM). It is found that 1-(P, P) and 1-(M, M) have opposite chiral properties due to the inversion of the structure. [ABSTRACT FROM AUTHOR]

The transverse magnetic electron scattering form factors of 19O and 21Na exotic nuclei were studied in the plane wave Born approximation (PWBA). The shell model calculations with three sd-shell interactions, USDA, USDB, and Wildenthal, were carried out for the ground and low-lying excited states. The exact center of mass correction in the Born approximation picture through the translation-invariant shell model (TISM) was included to modify the transverse form factors. The measured magnetic dipole moments were well reproduced with the core polarization (CP) effect introduced through the effective g-factors. The occupancies percentage with respect to the valence nucleons was also calculated. [ABSTRACT FROM AUTHOR]

Electrical control of magnetization or magnetic control of polarization offers an extra degree of freedom in materials possessing both electric and magnetic dipole moments, viz., magnetoelectric (ME) multiferroics. A microstructure with polycrystalline configurations that enhances the overall polarization/magnetization and that outperforms single crystalline configurations is identified in a 1–3 CoFe 2 O 4 –BaTiO 3 (or CFO–BTO) composite. The characterization of local fields corresponding to the polycrystal configuration underlines a nontrivial role played by randomness in better cross coupling mediated by anisotropic and asymmetric strains. The microscopic field (local field) profile of the composite provides rich information regarding the distribution of key parameters central to the magnetoelectric effect. The differential contractual stress level observed in the local stress profile of CFO–BTO composite upon applying an external magnetic field conforms with the previous experimental magnetostriction observed in CFO. The role played by residual stresses stemming from misalignment of the polarization in the neighboring grains in enhancing the ME coupling is briefly discussed. [ABSTRACT FROM AUTHOR]

Circularly polarized light (CPL) carrying spin angular momentum is crucial to many applications, such as quantum computing, optical communication, novel displays, and biosensing. Nonetheless, the emission from chiral molecules contains comparable CPL components with opposite handedness, resulting in low levels of CPL overall with a small dissymmetry factor and fixed handedness consistent with the handedness of the molecules. Nanoantennas have proved to be useful tools for controlling the emission properties of quantum emitters. In particular, dielectric resonators support electric and magnetic modes, which implies unparalleled opportunities to interact with chiral molecules whose emission originates from both electric and magnetic dipole transitions. In this work, we theoretically study the effects of a spherical dielectric nanoantenna on the directionality and polarization of emission from a chiral molecule. With exact analytical solutions based on generalized Mie theory, we show that directional chiral light emission and nontrivial polarization modulation, such as handedness reversal or chirality enhancement, can be achieved simultaneously for a chiral dipole tangentially coupled with a silicon nanosphere. The influence of the relative strength and orientation between the electric and magnetic dipole moments is also discussed. Our results suggest a new approach to controlling chiral dipolar emission and could benefit the development of chiral light sources. [ABSTRACT FROM AUTHOR]

We reported the synthesis of a series of structurally diverse CPL‐active molecules, in which pyrene units were installed to chiral pm/po‐[2,2]PCP scaffolds either with or without a triple bond spacer for pm/po‐PCP‐P1 and pm/po‐PCP‐P2, respectively. The X‐ray crystallographic analyses revealed that these pyrene‐based [2,2]PCP derivatives exhibited diverse structures and crystal packings in the solid phases. The pyrene‐based [2,2]PCP derivatives exhibit various (chir)optical properties in organic solutions, depending on their respective structures. In a mixture of dioxane and water, pm/po‐PCP‐P1 emit green excimer fluorescence, whereas pm/po‐PCP‐P2 emit blue one. The chiroptical investigation demonstrated that Rp‐pm‐PCP‐P1 and Rp‐pm‐PCP‐P2 exhibited completely opposite CD and CPL signals even they possess the same chiral Rp‐[2,2]PCP core. The same argument also holds for other chiral pyrene‐based [2,2]PCP derivatives. The theoretical calculation revealed that these unusual phenomena were attributed to different orientation between transition electric dipole moments and the magnetic dipole moments originating from the presence or absence of a triple bond spacer. These pyrene‐based [2,2]PCP derivatives display various colours and fluorescence emissions in the solid state and PMMA films, possibly due to the different packings as observed in the crystal structure. Moreover, these compounds also can interact with perylene diimide through π‐π interactions, leading to near‐white fluorescence. [ABSTRACT FROM AUTHOR]

The magnetic dipole moment and the electric quadrupole moment are the nuclear moments that provide us with key information about the proton and neutron configurations in a nucleus and the shape of a nucleus, respectively. In the study of nuclear structure through the measurement of the nuclear moments, a technique to produce spin orientation of rare-isotope beams has played important roles. Recently, a scheme of the two-step projectile fragmentation was developed to produce high spin alignment in RI beams and was applied to the frontier of the study for nuclear structure of neutron-rich nuclei, such as 75 Cu and 99 Zr. The recent activities of the nuclear-moment measurements using highly spin-aligned beams at RIKEN RIBF are reported. [ABSTRACT FROM AUTHOR]

Herein, we report the first example of chiral donor–acceptor cage DA-2 displaying efficient circularly polarized thermally activated delayed fluorescence (CP-TADF) with ‖glum‖ values up to 2.1 × 10−3 and PLQY of 32%. A small ΔEST of 0.051 eV and quasi-parallel (= 6°) transition electric and magnetic dipole moments were realized from the through-space charge transfer interaction between the parallelly aligned donor and acceptor in DA-2. This D–A cage configuration has provided a novel design strategy for discovering potential efficient CP-TADF emitters. [ABSTRACT FROM AUTHOR]

The interaction between sites A, B and X with passivation molecules is restricted when the conventional passivation strategy is applied in perovskite (ABX3) photovoltaics. Fortunately, the revolving A-site presents an opportunity to strengthen this interaction by utilizing an external field. Herein, we propose a novel approach to achieving an ordered magnetic dipole moment, which is regulated by a magnetic field via the coupling effect between the chiral passivation molecule and the A-site (formamidine ion) in perovskites. This strategy can increase the molecular interaction energy by approximately four times and ensure a well-ordered molecular arrangement. The quality of the deposited perovskite film is significantly optimized with inhibited nonradiative recombination. It manages to reduce the open-circuit voltage loss of photovoltaic devices to 360 mV and increase the power conversion efficiency to 25.22%. This finding provides a new insight into the exploration of A-sites in perovskites and offers a novel route to improving the device performance of perovskite photovoltaics. [ABSTRACT FROM AUTHOR]

Precise measurement of stellar properties through the observation of continuous gravitational waves from spinning non-axisymmetric neutron stars can shed light onto new physics beyond terrestrial laboratories. Although hitherto undetected, prospects for detecting continuous gravitational waves improve with longer observation periods and more sensitive gravitational wave detectors. We study the capability of the Advanced Laser Interferometer Gravitational-Wave Observatory, and the Einstein Telescope to measure the physical properties of neutron stars through continuous gravitational wave observations. We simulate a population of Galactic neutron stars, assume continuous gravitational waves from the stars have been detected, and perform parameter estimation of the detected signals. Using the estimated parameters, we infer the stars' moments of inertia, ellipticities, and the components of the magnetic dipole moment perpendicular to the rotation axis. The estimation of the braking index proved challenging and is responsible for the majority of the uncertainties in the inferred parameters. Using the Einstein Telescope with an observation period of |$5\, {\rm {yr}}$|⁠ , point estimates using median can be made on the moments of inertia with error of |$\sim 10\!-\!100~{{\ \rm per\ cent}}$| and on the ellipticities with error of |$\sim 5\!-\!50~{{\ \rm per\ cent}}$|⁠ , subject to the inference of the braking index. The perpendicular magnetic dipole moment could not be accurately inferred for neutron stars that emit mainly gravitational waves. [ABSTRACT FROM AUTHOR]

Magnetic Field Assisted Additive Manufacturing (MFAAM) enables 3D printing of magnetic materials of various shapes which exhibit a complex anisotropy energy surface containing contributions generated from different origins such as sample, particle, and agglomerate shape anisotropy, flow and field induced anisotropy, and particle crystal anisotropy. These novel magnet shapes require the need to measure the x, y, and z components of the magnetic dipole moment simultaneously to fully understand the magnetic reversal mechanism and unravel the complex magnetic anisotropy energy surface of 3D printed magnetic composites. This work aims to develop a triaxial vibrating sample magnetometer (VSM) by adding a z-coil set to a pre-existing biaxial VSM employing a modified Mallison coil set. The optimum size and location of the sensing coils were determined by modeling the sensitivity matrix of the z-coil set. The designed coil set was implemented using 3D printed spools, a manual coil winder, and gauge 38 copper wire. A 3D printed strontium ferrite nylon composite sample was used to estimate the sensitivity of the z-coils (50 mV/emu). The results herein are applicable for any VSM using a modified Mallison biaxial coil configuration allowing for a quick implementation on pre-existing systems. [ABSTRACT FROM AUTHOR]

Chiral molecules play important roles in advanced materials and technologies owing to their unique chiroptical properties. How to design and construct the best chiral molecules with intrinsically strong chiroptical properties is still a great challenge since there is an intrinsic contradiction between the large absorption dissymmetry factor and oscillator strength. In this work, through a systematic theoretical investigation, it is found that chiral cylindrical molecules could overcome this problem through accumulating the electric and magnetic transition dipole moment along the cylindrical axis direction while canceling them in other directions. Among all the investigated structures, (M)‐[8]CC2,8 is found to exhibit the best chiroptical properties with gabs of 0.71 and oscillator strength of 0.032. To the best of our knowledge, this is the best chiral molecule with both large dissymmetry factor and oscillator strength. Further increasing the repeating units, the gabs can even reach the theoretical limit of 2 for (M)‐[28]CC2,8, together with a large oscillator strength of 0.134. The result offers the exciting opportunities for designing and synthesizing chiral materials with truly large intrinsically chiroptical properties toward real applications in chiroptoelectronic and chiro‐spintronic devices. [ABSTRACT FROM AUTHOR]

Throughout this work, we explored the dynamics of test particles with magnetic dipole moment around magnetized rotating Kerr black holes in scalar–vector–tensor gravity theory (STVG), known as modified gravity theory (MOG). We assume that the black hole is immersed in external asymptotically uniform magnetic fields. We derive effective potential for circular orbits of the magnetized particles, taking into account both the magnetic and STVG interactions. We study profiles of the position of the innermost stable circular orbits (ISCOs) of the magnetized particles. We show that the MOG interaction is essentially, and the magnetic interaction enhances its effects on the ISCO radius and the angular momentum at ISCO. Also, we consider collisional cases of magnetized particles and the maximum and minimum limits of angular momentum that ensure the particle colliding near the horizon. Finally, we analyze the center-of-mass energy of colliding magnetized particles near the black hole horizon. [ABSTRACT FROM AUTHOR]

An isolated pulsar is a rotating neutron star possessing a very high magnetic dipole moment, thus providing a powerful radiating mechanism. These stars loose rotational energy E through various processes, including a plasma wind originating from a highly magnetized magnetosphere and the emission of magnetic dipole radiation (MDR). Such phenomena produce a time decreasing angular velocity Ω(t) of the pulsar that is usually quantified in terms of its braking index. Although these mechanisms are widely acknowledged as the primary drivers of the spin evolution of isolated pulsars, it is plausible that other contributing factors influencing this effect have yet to be comprehensively investigated. Most of young isolated pulsars present a braking index different from that given by the MDR and plasma wind processes. Working in the weak field (Newtonian) limit, we take in this work a step forward in describing the evolution of such a system by allowing the star's shape to wobble around an ellipsoidal configuration as a backreaction effect produced by its rotational deceleration. It is assumed that an internal damping of the oscillations occurs, thus introducing another form of energy loss in the system, and this phenomenon may be related to the deviation of the braking index from the models based on |$\dot{E} \sim -\Omega ^4$| predictions. Numerical calculations suggest that the average braking index for typical isolated pulsars can be thus explained by a simple phenomenological model. [ABSTRACT FROM AUTHOR]

The development of chiral compounds with enhanced chiroptical properties is an important challenge to improve device applications. To that end, an optimization of the electric and magnetic dipole transition moments of the molecule is necessary. Nevertheless, the relationship between chemical structure and such quantum mechanical properties is not always clear. That is the case of magnetic dipole transition moment (m) for which no general trends for its optimization have been suggested. In this work we propose a general rationalization for improving the magnitude of m in different families of chiral compounds. Performing a clustering analysis of hundreds of transitions, we have been able to identify a single group in which |m| value is maximized along the helix axis. More interestingly, we have found an accurate linear relationship (up to R2=0.994) between the maximum value of this parameter and the area of the inner cavity of the helix, thus resembling classical behavior of solenoids. This research provides a tool for the rationalized synthesis of compounds with improved chiroptical responses. [ABSTRACT FROM AUTHOR]

Multidimensional spin-selective manipulation of optical waves is crucial for various intriguing applications in modern nanophotonics, such as quantum-information processing and chiral sensing and imaging. In this work, we observed giant broadband asymmetric transmission of circularly polarized waves and spin-preserving reflection, together with near-unity transmission circular dichroism, in a planar chiral metasurface composed of high-index transition-metal-dichalcogenide nanoantennas with large material anisotropy. The perpendicular and parallel electric and magnetic dipole moments excited in the nanoantennas under circularly polarized waves are explored to account for the asymmetric transmission and optical chirality. Combined with the Pancharatnam–Berry phase, we achieved the wavefront manipulation for transmitted circularly polarized waves with an efficiency approaching 91.5% and spin-selective focusing of an incident light via a metasurface metalens. Our work will pave the way for studying the multidimensional manipulation of optical spins through engineering transition-metal-dichalcogenide-based metasurfaces. [ABSTRACT FROM AUTHOR]

Herein a series of chiral BTI radical anions bearing different chiral substituents were efficiently prepared by chemical reduction. X‐ray crystallography revealed finely‐tuned packing and helix assemblies of the radicals by the size of chiral substituents in crystalline state. In accordance with the crystalline‐state packing, the powder ESR spectra indicate that 4 a−⋅CoCp2+ and 4 c−⋅CoCp2+ π‐dimers exhibit thermally excited triplet states arising from strong spin‐spin interactions, while discrete 4 b−⋅CoCp2+ shows a broad doublet‐state signal reflecting weak spin‐spin interactions. The interplay between the unpaired electron spin and chiral substituents was studied by UV‐Vis‐NIR spectra, electronic circular dichroism (ECD) and TD DFT calculations. Different NIR absorptions of the radicals attributing to isolated SOMO→LUMO+1 (~889 nm) transitions were recorded. The emergence of Cotton effects (CEs) at the NIR region for 4 c−⋅CoCp2+ radical enantiomers suggest the interplay between chirality and unpaired electron spin. The origin of the different circularly polarized light absorptions regarding SOMO derived transitions (around 880 nm) was attributed to chiral substitutes regulated electric and magnetic transition dipole moments of the unpaired electron participated transition. [ABSTRACT FROM AUTHOR]

Two dimensional all dielectric grating metamaterial based on polydimethylsiloxane and TiO2 materials were prepared via sputtering method in two different configurations as PDMS/TiO2 (50 nm)) and 2D grating (etalon) TiO2 (50 nm)/PDMS/TiO2 (50 nm). As it was measured by a charged coupled device (CCD) camera, the hotspots confirm four points symmetry of the structure and also the refractive index falls in the negative part to show meta state. In addition, the absorption spectra show the clear separation between electric dipole (ED) and Magnetic dipoles (MD) by enhancing the incidence angle onto the sample. We noted the gradual increase in the angle begins to appear and became more noticeable from 52o to 60o and the reason for this separation at these angles may be the fall of the beam at an oblique angle, and it is clear that inclination at an oblique angle leads to a more pronounced metamaterial behavior. [ABSTRACT FROM AUTHOR]

The Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites (TRACERS) Small Explorers mission requires high-fidelity magnetic field measurements for its magnetic reconnection science objectives and for its technology demonstration payload Magnetometers for Innovation and Capability (MAGIC). TRACERS needs to minimize the local magnetic noise through a magnetic cleanliness program such that the stray fields from the spacecraft and its instruments do not distort the local geophysical magnetic field of interest. Here we present an automated magnetic screening apparatus and procedure to enable technicians to routinely and efficiently measure the magnetic dipole moments of potential flight parts to determine whether they are suitable for spaceflight. This procedure is simple, replicable, and accurate down to a dipole moment of 1.59 × 10 -3 N m T -1. It will be used to screen parts for the MAGIC instrument and other subsystems of the TRACERS satellite mission to help ensure magnetically clean measurements on orbit. [ABSTRACT FROM AUTHOR]

In the framework of the MSSM extension with local gauged baryon and lepton numbers (BLMSSM), we calculate the muon anomalous magnetic dipole moment (MDM) and lepton (e, μ, τ) electric dipole moment (EDM), and discuss how the muon MDM and lepton EDM depend on the parameters within the mass insertion approximation. Among many parameters, tan β , g L , m L and μ H are more sensitive parameters for a μ BL . Considering the experimental limitations, our best numerical result of a μ BL is around 2.5 × 10−9, which can well compensate the departure between the experiment data and standard model (SM) prediction. The CP violating phases in BLMSSM are more than those in the MSSM, including new parameters θ μ L and θ L . They can give large contributions, which play an important role in exploring the source of CP violation and probing new physics beyond SM. [ABSTRACT FROM AUTHOR]