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For the pnictogen atoms, the first two levels 4 S ∘ and 2 D ∘ may couple together through the spin–orbit coupling (SOC) effects with the aid of the third level 2 P ∘ , leading to a complicated computational procedure to take SOC into account. In this work, we theoretically study the low-lying valence states of BiPn (Pn = N, P, As, and Sb), where 102 Λ -S states from nine dissociation asymptotes split into 242 Ω states. In view of too many Λ -S and Ω states, some special treatments have been considered. In the Λ -S state calculation, which is the most computationally intensive part, we employ the recently developed multi-reference configuration interaction (MRCI) method in the efficient static-dynamic-static (SDS) framework. The more reliable two-component MRCI method has also been performed to compute some spectroscopic parameters for validation. The calculated spectroscopic constants of low-lying Ω states are generally in good agreement with the available experimental ones, but the experimental dissociation energies of BiP and BiSb seem seriously underestimated and need to be remeasured. Some new spectral transitions have also been predicted, which provide useful references for future experiments. • Highly accurate ab initio calculations of BiPn (Pn = N, P, As, and Sb) with scalar relativistic effect and spin–orbit coupling. • Potential energy curves and spectroscopic constants of low-lying Ω states of BiP, BiAs, and BiSb are obtained for the first time. • Reliable dissociation energies of the four molecules are reported. • New transitions that may be detected in absorption and emission spectra are suggested. [ABSTRACT FROM AUTHOR]

Melilite structural materials have been widely studied in the past two decades due to their interesting physical properties, such as noncollinear magnetism and multiferroicity. Here, we present a theoretical investigation on the electronic and magnetic properties of melilite structural materials Ba 2 FeSi 2 O 7 and Ba 2 CoGe 2 O 7. First-principles calculations confirm that Ba 2 FeSi 2 O 7 and Ba 2 CoGe 2 O 7 are both antiferromagnetic semiconductors with the magnetic easy axis being along the [110] direction. Two flat bands with a bandwidth of less than 20 meV, which come from the d 3 z 2 − r 2 orbitals of Fe2+ or Co2+ ions, are found in both materials. More interestingly, we find that the magnetocrystalline anisotropy energy of the Ba 2 FeSi 2 O 7 is about 5.19 meV per unit cell, which is more than eight times larger than that of Ba 2 CoGe 2 O 7. Further calculations show that their MAEs are mainly contributed by the single-ion anisotropy. The perturbation calculations indicate that the different electron numbers in the d orbitals and their different orbital occupations in the two materials lead to the large difference in their single-ion anisotropy. Our work could be helpful to understand the magnetic behaviors in similar melilite structural materials. • The magnetic properties of Ba 2 FeSi 2 O 7 and Ba 2 CoGe 2 O 7 are studied by the DFT calculations. • Two flat bands with a bandwidth of less than 20 meV are found in Ba 2 FeSi 2 O 7 and Ba 2 CoGe 2 O 7. • Ba 2 FeSi 2 O 7 has a large MAE of 5.19 meV per unit cell, which is more than eight times larger than that of Ba 2 CoGe 2 O 7. • The different orbital occupations lead to the large differences in their single-ion anisotropy. [ABSTRACT FROM AUTHOR]

We investigated the existence and stability of solitons in parity-time optical lattice with pseudo spin-orbit coupling (SOC). The numerical results show that the symmetry of solitons still accords with the characteristics of traditional parity-time (PT) soliton symmetry. Due to the existence of PT optical lattice, the polarization component of solitons is not purely real or purely imaginary. And the strength of SOC has a significant impact on the band-gap structure of the system. • The soliton symmetry in PT lattice with pseudo SOC accords with traditional PT soliton one. • Due to the existence of PT optical lattice, the polarization component of solitons is not purely real or purely imaginary. • The strength of SOC has a significant impact on the band-gap structure of the system. [ABSTRACT FROM AUTHOR]

A considerably enhanced Rashba coefficient, α of up to ∼1.7 e V Å in single layer graphene (SLG) on Ni(111) in bridge-top (BT) configuration is obtained using density functional theory with spin-orbit coupling calculations. This is attributed to significant proximity and exchange effects in the BT configuration of SLG/Ni arising from a direct and enhanced Ni- d z 2 interaction with SLG- π states. The Rashba and exchange splitting occur in the graphene bands directly above and below the E F in the dispersion along the M − K − M ′ path, that is involving the Dirac point. No Rashba splitting is noted along Γ − M direction in agreement with angle-resolved photoemission spectroscopy (ARPES). The above results reveal the specific conformation of SLG on ferromagnetic substrate different from the commonly studied top-fcc (TF) structure and paves the way for SLG for spin-orbitronics without the need for interfacing or intercalating heavy and precious metals. [Display omitted] • Enhanced Rashba + exchange splittings found in bridge-top structure graphene on Ni. • Rashba coefficient of up to 1.7 e V Å , close to/higher than the conventional systems. • Proximity effect via the Ni- d z 2 interaction with SLG- π states proposed. • No Rashba splitting found at Γ − M dispersions confirming ARPES results. • Large Rashba + exchange effects obtained without using precious or heavy metals. [ABSTRACT FROM AUTHOR]

[Display omitted] The quest for efficient and sustainable energy solutions has led to the exploration of novel materials for photovoltaic cells (PVC). Copper chalcogenides, particularly Cu 2 ZnSnS 4 (CZTS), have emerged as promising candidates due to their abundance and low toxicity. However, CZTS suffers from efficiency limitations attributed to crystal quality and structural instability. Substitutional alloying offers a pathway to enhance CZTS properties, yet challenges persist in achieving significant efficiency gains. This study investigates the substitutional effect of titanium (Ti) in CZTS through ab initio calculations using the generalized gradient approximation plus Hubbard U correction (GGA+ U). Specifically, Ti is substituted at various concentrations in Sn sites to explore its impact on electronic and optical properties. The study employs density functional theory (DFT) calculations to elucidate the structural, electronic and optical characteristics of Ti-substituted CZTS alloys. Notably, the inclusion of effective spin–orbit coupling (SOC) within the GGA+ U framework enhances the accuracy of band gap predictions. Results reveal that Ti substitution enlarges the band gap, thereby improving the absorption coefficient spectrum, indicative of potential applications in enhancing CZTS PVC efficiency. Overall, this work underscores the importance of alloying strategies in tailoring the functional properties of CZTS for advanced PVC applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rhombohedral phase of hematite and Si-doped films deposited on SiO 2 /Si substrate. • Correlation between elemental profile and phase established using GI-XRD and RBS techniques. • Suppression of two-magnon mode and surface FM confirmed in Si-doped hematite film. • The films with low reflectivity, high refractive index (2.23–2.61) and optical band gap (2.30–3.68 eV) can be used for anti-reflecting glass. • The Si doped hematite films with soft ferromagnetism applicable in spintronics devices. Thermal evaporation technique has been used to synthesize the α-Fe 2 O 3 (hematite) and Si-doped hematite films on three different substrates (SiO 2 /Si, Al 2 O 3 and quartz). The post-deposition heat treatment at 800 °C has further improved the crystalline nature of the films. Rutherford backscattering spectroscopy has provided information for surface elemental composition and depth profile. Raman spectra have supported the formation of rhombohedral phase and inter-layer diffusion between substrate and films. The x-ray photoelectron spectroscopy has confirmed the mixed-valence oxidation states for Fe ions and +4 state for the Si ions in Si-doped hematite films. The optical reflectance spectra in the UV–Visible region indicated contributions from the films and film-substrate interface. The Si-doping has enhanced soft ferromagnetic properties in the hematite film with noticeable decrease of the magnetic coercivity and increase of the magnetic moment. The films showed blocking of magnetization at lower temperatures, typically below 125 K, and a wide thermomagnetic irreversibility between zero-field cooled and field cooled magnetization curves. The modified surface chemical structure, ferromagnetism and optical properties in the Si doped hematite films promise their potential applications in spintronics. [ABSTRACT FROM AUTHOR]

Some theoretical studies using perturbation and tight-binding methods have tried to shed light on the magnetic behaviors of carbon-based nanostructures in the limit of wave vector q=0\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\mathbf {q=0}$$\end{document}. In a recent work, we studied a half-filled model of helical carbon chains to gain new insights for q≠0\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\mathbf {q \ne 0}$$\end{document}. Although in carbon the energy bands are usually derived from partially filled atomic p-shells, here we explore the hole contribution to these magnetic responses. We calculate the longitudinal spin susceptibility of an almost-filled tight-binding model of a helical chain for q≠0\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\mathbf {q\ne 0}$$\end{document}. We find that when the Fermi level lies at the band edges, the system shows for positive chirality a divergent paramagnetic susceptibility. This result is in agreement with that previously reported for the macroscopic limit q=0\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\mathbf {q=0}$$\end{document}. [ABSTRACT FROM AUTHOR]

[Display omitted] • The proximity of the 4d10 5p1 (2Po) and 4d9 5s2 (2D) excited states of silver and the presence of spin–orbit coupling makes the study of excited states of silver-containing molecules challenging. • Low-lying electronic states of AgH have been calculated using the multireference configuration interaction method incorporating scalar relativistic effects and spin–orbit coupling corrections. • Potential energy curves and spectroscopic constants were obtained for 24 individual Ω states, with an accurate description of the excited states of AgH after spin–orbit corrections. • Several excited states observed in the ultraviolet absorption spectra of AgH and AgD have been relabeled using the new ab initio data. Potential energy curves have been calculated for the low-lying electronic states of AgH, correlating to the 4d10 5s1 (2S), 4d10 5p1 (2Po), 4d9 5s2 (2D), and 4d10 6s1 (2S) states of atomic silver, using the MRCI method with scalar relativistic and spin–orbit corrections. Spectroscopic constants were obtained for 24 individual Ω states, and several excited states of AgH observed in the ultraviolet absorption spectra, i.e., the C1Π, B1Σ+, b3Δ 1 , and D1Π states, were relabeled based on the new ab initio data. The calculated Einstein A coefficients indicated that almost all electronic transitions with ΔΩ = 0, ±1 are allowed. [ABSTRACT FROM AUTHOR]

\nIMPACT STATEMENTFirst-principles calculations incorporating spin-orbit coupling are presented for a multiferroic material as a ferromagnetic/ferroelectric junction. We simulate the interface effect that cannot be described by the single-phase bulk. The in-plane uniaxial magnetic-anisotropy of Co2FeSi is observed when the ferroelectric domain is polarized parallel to the interface, whereas the magnetic anisotropy is significantly different in the plane for the electrical polarization perpendicular to the interface. While the single-phase effect dominates the main part of the modulation of the magnetic anisotropy, symmetry breaking due to the interfacial effect is observed in the ferromagnetic ultrathin films. The origin of the modulated magnetic-anisotropy can be attributed to the shifting of specific energy bands in Co2FeSi when the ferroelectric domain is modified.The origin of strain-induced magnetocrystalline anisotropy in multiferroic Co2FeSi/BaTiO3(001) heterostructures is clarified by first-principles electron theory. The magnetic anisotropy is modified by interface effects for ultrathin Co2FeSi films. [ABSTRACT FROM AUTHOR]

This study employed density functional theory calculations to provide predictions regarding the optoelectronic and thermoelectric properties of both pristine and defective CsSnCl 3 in their respective cubic and tetragonal phases. In this study, we provide novel findings about the influence of spin-orbit coupling (SOC) on the optical and thermoelectric characteristics of these systems. When considering the phenomenon of SOC, it is noticed that these materials have enhanced absorption capabilities in the visible range compared to their counterparts without SOC, owing to their unique band characteristics. The compounds, regardless of the inclusion of SOC, exhibit a figure of merit that is approximately equal to unity. This characteristic suggests that these materials hold promise as possible candidates for use in photovoltaics and thermoelectrics. [ABSTRACT FROM AUTHOR]

We consider a generalization of the Duffin–Kemmer–Petiau oscillator (DKPO) for spin-1 bosons, built by implementing an extra spin–orbit coupling (SOC) into the standard DKPO equation. This model meets the requirements of Lorentz covariance as well as the existence of a conserved four-current, and is found to be exactly solvable for both natural and unnatural parity states and for an arbitrary total angular momentum number. The obtained energy eigenvalues show that the additional SOC brings about radical modifications in the spectroscopy of the DKPO. Notably, the spin–orbit splitting of the energy levels becomes controllably independent from oscillator shells. Moreover, interesting particular cases of the model as well as its non-relativistic limit are discussed.

Spin-orbit coupling (SOC) in graphene can be greatly enhanced by proximity coupling it to transition metal dichalcogenides (TMDs) such as WSe2. We find that the strength of the acquired SOC in graphene depends on the stacking order of the heterostructures when using hexagonal boron nitride ( h-BN) as the capping layer, i.e., SiO2/graphene/WSe2/ h-BN exhibiting stronger SOC than SiO2/WSe2/graphene/ h-BN. We utilize photoluminescence (PL) as an indicator to characterize the interaction between graphene and monolayer WSe2 grown by chemical vapor deposition. We observe much stronger PL quenching in the SiO2/graphene/WSe2/ h-BN stack than in the SiO2/WSe2/graphene/ h-BN stack and, correspondingly, a much larger weak antilocalization (WAL) effect or stronger induced SOC in the former than in the latter. We attribute these two effects to the interlayer distance between graphene and WSe2, which depends on whether graphene is in immediate contact with h-BN. Our observations and hypothesis are further supported by first-principles calculations, which reveal a clear difference in the interlayer distance between graphene and WSe2 in these two stacks.

The insight that optical vortex beams carry orbital angular momentum (OAM), which emerged in Leiden about 30 years ago, has since led to an ever expanding range of applications and follow-up studies. This paper starts with a short personal account of how these concepts arose. This is followed by a description of some recent ideas where the coupling of transverse orbital and spin angular momentum (SAM) in tightly focused laser beams produces interesting new effects. The deflection of a focused light beam by an atom in the focus is reminiscent of the Magnus effect known from aerodynamics. Momentum conservation dictates an accompanying light force on the atom, transverse to the optical axis. As a consequence, an atom held in an optical tweezer will be trapped at a small distance of up to λ/2π away from the optical axis, which depends on the spin state of the atom and the magnetic field direction. This opens up new avenues to control the state of motion of atoms in optical tweezers as well as potential applications in quantum gates and interferometry.

Abstract Spin injection across interfaces driven by ultrashort optical pulses on femtosecond timescales constitutes a new way to design spintronics applications. Targeted utilization of this phenomenon requires knowledge of the efficiency of non‐equilibrium spin injection. From a quantitative comparison of ab initio time‐dependent density functional theory and interface‐sensitive, time‐resolved non‐linear optical experiment, the spin injection efficiency (SIE) at the Co/Cu(001) interface is determined, and its microscopic origin, i.e., the influence of spin‐orbit coupling and the interface electronic structure, is discussed. Moreover, we theoretically predict that the SIE at ferromagnetic–metal interfaces can be optimized through laser pulse and materials parameters, namely the fluence, pulse duration, and substrate material.

Methyl substitution in ortho position causes a deshielding of 6–7 ppm on the 13C NMR chemical shift of the own methyl group and the carbon nucleus bonded to iodine atom (ipso) in iodobenzene-like molecules. In contrast, the carbon ipso is 3–4 ppm shielded when methyl is in para. To understand how the position of methyl substitution perturbs nuclear magnetic responses in iodobenzene and diacetoxyiodobenzene derivatives, shielding mechanisms are theoretically investigated via density functional theory calculations. We show the relative ortho position between iodine and methyl allows through-space and through-bond interactions to take place, generating additional paramagnetic currents and affecting the spin-orbit coupling propagation. Relevant paramagnetic couplings that explain the para methyl substitution behavior are also presented. Shielding mechanisms discussed here for monomethylated compounds can be summed to predict the 13C NMR chemical shift in multi methyl substituted iodine-containing compounds.

The spin-valley-related electronic properties of quasi-one-dimensional kagome lattices with intrinsic spin-orbit coupling are studied, based on the tight-binding formalism. Three types of kagome-lattice nanoribbons along the x-direction with various geometric boundaries are proposed, including two symmetric nanoribbons and one asymmetric one. It is found that two nonequivalent Dirac cones and helical edge states exist in all the three types of kagome-lattice nanoribbons at 1/3 filling. Among them in the asymmetric nanoribbon, the spin and valley are found to be locked to each other due to inversion symmetry breaking, resulting in spin-valley polarized edge states. Band structure and probability density of wave function show that the spin-up/-down edge states locate at the K/K′ valley, with opposite propagation direction at the upper and lower boundaries. Spin-resolved real-space local current confirms the spin-valley polarized helical edge state in the asymmetric nanoribbon. The device application of the asymmetric kagome-lattice nanoribbon is worth further investigation.

We theoretically investigate the energy band structure, nonlinear Landau–Zener tunneling dynamics and tunneling probability of spin-orbit coupled Bose–Einstein condensates in a one-dimensional accelerating optical lattice by using mean-field and two-mode approximation. The critical condition for the appearance of the loop structure is obtained numerically in parameter planes. When the intraspecies atomic interaction is less than the interspecies atomic interaction, the loop only appears in the lower band. In this case, Raman coupling inhibits the appearance of loop, while spin-orbit coupling (SOC) promotes the appearance of loop. If the intraspecies atomic interaction is larger than interspecies atomic interaction, the loop can appear in either the upper band or the lower band. In this case, Raman coupling promotes the loop appearing in the lower band, while SOC suppresses the loop appearing in upper band. Interestingly, when the interspecies atomic interaction is equal to the intraspecies atomic interaction, there is a critical atomic intercation value determined by the optical lattice depth, only when the intraspecies atomic interaction is greater than the critical value, the loop will occur only in lower band. Especially, the emergence of the loop structure destroys the Bloch oscillation of the system and results in the nonlinear Landau–Zener tunneling of the system. Furthermore, the Landau–Zener tunneling probability of the system is calculated, and it is found that the nonlinear Landau–Zener dynamics and the tunneling probability can be manipulated by SOC and Raman coupling. [ABSTRACT FROM AUTHOR]

Summary: 2D Ruddlesden‐Popper (RP) perovskites (R‐NH3)2An−1BnX3n+1 with tailorable photovoltaic features of low toxicity, reduced dimensionality, and defect tolerance hold promise to overcome the main constraints of perovskite solar cells (PSCs). A systematic investigation of the structural and electronic properties of pure and mixed (R‐NH3)2Pb1−xGexI4 systems was performed with and without spin‐orbit coupling (SOC), by using density functional theory (DFT). The organic spacer cations (R‐NH3+)2 of methylammonium (MA‐CH3NH3+) and Phenylethyl ammonium (PEA‐C6H5[CH2]2NH3+) with x = 0.0, 0.25, 0.50, 0.75, 1.0, resulted in the compositionally modified 32‐permutations by systematically substituting the inorganic cations. Short‐range ordering has categorized all studied compositions of (R‐NH3)2Pb0.50Ge0.50I4 into column and battenberg schemes depending on the Ge defect site. The competing effects of octahedral tilting and lattice distortion with bandgap bowing and SOC, across Pb‐Ge compositional systems, provide a systematic strategy to tune bandgaps. By controlling the cations' composition, these mixed 2D‐perovskites outlined the strategy to achieve the desired bandgap and band positions. A rational design approach of low dimensional perovskites was adopted to tune the electronic properties through the spacer and inorganic cation engineering. Our findings expose the scope of monolayer‐based systems as an ideal choice of absorber for the bottom sub‐cell in all‐perovskites 2D‐3D tandem solar cell, harvesting light from visible (2.4 eV) up to infrared (1.2 eV) in the solar spectrum with features of defect tolerance, quantum and dielectric confinement, low bandgap, low effective masses, and high mobility. [ABSTRACT FROM AUTHOR]

Cu(I) complexes have received widespread attention as a promising alternative to traditional noble-metal complexes. Herein, we systematically study the properties of Cu(I) complexes from homo- to hetero-ligands, and found the following: (1) hetero-ligands are beneficial to regulate phosphorescent efficiency; (2) when the hetero-ligands in a tetracoordinated Cu(I) complex are 1:1, the ligands coordinate along the dx2-y2 direction of Cu(I) ion, which can observably suppress structural deformation; (3) unlike the P^P ligand, the N^N ligand can enhance the participation of Cu(I) during the transition process; (4) the addition of an appropriate amount of P^P ligand can effectively raise the energy level of HOMO (highest occupied molecular orbital), enhance the proportion of LLCT (ligand–ligand charge transfer), and thereby increase the available singlet emission transition moments which can be borrowed, thus promoting the radiative decay process. As a result, this work provides a detailed understanding of the effects of different ligands in Cu(I) complexes, and provides a valuable reference and theoretical basis for regulating and designing the phosphorescent properties of Cu(I) complexes in the future. [ABSTRACT FROM AUTHOR]

The splitting of spin levels generating minigaps under the action of twisting a non-chiral (7, 7) silicon nanotube around its axis has been studied by the relativistic method of symmetrized linearized augmented cylindrical waves. In the absence of mechanical twisting, the nanotube has inversion symmetry and metallic band structure with spin-degenerate states in the Fermi region. Torsion deformation breaks the inversion symmetry, transforming the nanotube into a chiral system. Due to the joint action of the spin–orbit coupling and the deformation perturbation, the degeneracy of the levels is completely lifted and states with spins up and down are formed. Opposite directions of twisting lead to the reversal of the order of spin levels and can induce oppositely directed spin currents, which is important for the design of elements of nanoelectronics and spintronics. [ABSTRACT FROM AUTHOR]

We use a discrete element method to simulate the tidal evolution of the spin of a viscoelastic circular body (a secondary body) moving in a circular orbit under the attraction of a large point-mass (a primary body) located at the centre, where the secondary body can have general elasticity (e.g. variable Poisson's ratio). The model consists of a group of rigid particles linked by elastic and dissipative springs and allows for translational and bending degrees of freedom and rotation of particles. The tidal deformation of the secondary body when it is orbiting around the primary body under the gravitational attraction, and a small lag angle between the direction of the bulge and a line that connects the two bodies have been reproduced. We measure the angular velocity evolution of the secondary body for different initial angular velocities. It is found that if the initial angular velocity is set as the special value (the locked angular velocity) such that the spin period equals its orbital period, the angular velocity of this body remains constant, indicating a stable "locked state". However, if the initial angular velocity is smaller/larger than the locked angular velocity, the body will spin up/down (i.e. its angular velocity will increase/decrease) due to the effect of tidal torque. Therefore, the spin velocity of an orbiting body (moon) will finally lock onto the orbiting period. Parameters which determine how rapidly the tidal locking occurs have been identified. These parameters include damping coefficient, the gravitational constant, the mass of the primary body, the distance between the primary and the secondary body, the rigidity parameter and Poisson's ratio of the secondary body, the radius of the secondary body and self-gravitation parameters. Tidal torques obtained from our simulations are compared with the one from the existing tidal theories and a good agreement is found. We demonstrate that the discrete element method is capable of directly simulating the deformation, spinning and tidal evolution of a viscoelastic object under tidal stress. [ABSTRACT FROM AUTHOR]

A new family of bis[pyrrolyl Ru(II)] triad scaffolds, consisting of two [Ru(bpy)2]2+ centers separated by a variety of organic linkers, has been recently reported as efficient compounds for in vitro photodynamic therapy (PDT). Among all the complexes, the one carrying the pyrenyl group in the organic linker, namely 4 h, has emerged as an extremely potent photosensitizer for in vitro PDT. Here, we present a computational study based on both DFT and TDA‐TDDFT methods, to investigate the photochemical properties of this promising complex. In order to evaluate the influence of the organic chromophore on the photochemical properties, our investigation was further extended to the complex 4 e, whose linker includes the benzothiadiazole group, which has yielded the longest‐wavelength absorption maxima overall (but with a reduced intensity compared to 4 h). Eventually, the role of the second [Ru(bpy)2]2+ moiety was evaluated by comparison with the mononuclear complex. [ABSTRACT FROM AUTHOR]

Investigations into potential topological materials yielded the new subiodide Sn[PtBi6I12]. The combination of thermal analyses with phase analyses of the products of isothermal ex situ syntheses allowed the establishment of a complex high‐temperature synthesis protocol for the crystal growth of the target phase despite the lack of knowledge of the quaternary phase diagram. A special challenge was to prevent the formation of competing compounds of the solid solution series (Bi2xSn1–3x)[PtBi6I12] with x≠0. Sn[PtBi6I12] crystallizes, isostructural to Pb[PtBi6I12], in the rhombohedral space group R3‾ with lattice parameters a=1583.2(2) pm and c=1089.70(10) pm. The compound consists of cuboctahedral [PtBi6I12]2− clusters and Sn2+ cations in an octahedral coordination between the trigonal faces of two cluster units, thereby concatenating them into infinite linear chains. The chains are connected via Bi⋯ I inter‐cluster bridges, creating a high‐entropy variant of the NaCl structure type. Sn[PtBi6I12] is a semiconductor with an experimental bandgap of 0.8(1) eV. Fully relativistic density functional theory calculations including an implementation of the bifunctional formalism for the exchange energy indicate a topologically trivial bandgap of 0.81 eV between bands that are dominated by contributions of bismuth and iodine. [ABSTRACT FROM AUTHOR]

Investigations into potential topological materials yielded the new subiodide Sn[PtBi6I12]. The combination of thermal analyses with phase analyses of the products of isothermal ex situ syntheses allowed the establishment of a complex high‐temperature synthesis protocol for the crystal growth of the target phase despite the lack of knowledge of the quaternary phase diagram. A special challenge was to prevent the formation of competing compounds of the solid solution series (Bi2xSn1–3x)[PtBi6I12] with x≠0. Sn[PtBi6I12] crystallizes, isostructural to Pb[PtBi6I12], in the rhombohedral space group R3‾ with lattice parameters a=1583.2(2) pm and c=1089.70(10) pm. The compound consists of cuboctahedral [PtBi6I12]2− clusters and Sn2+ cations in an octahedral coordination between the trigonal faces of two cluster units, thereby concatenating them into infinite linear chains. The chains are connected via Bi⋯ I inter‐cluster bridges, creating a high‐entropy variant of the NaCl structure type. Sn[PtBi6I12] is a semiconductor with an experimental bandgap of 0.8(1) eV. Fully relativistic density functional theory calculations including an implementation of the bifunctional formalism for the exchange energy indicate a topologically trivial bandgap of 0.81 eV between bands that are dominated by contributions of bismuth and iodine. [ABSTRACT FROM AUTHOR]

A tin–bismuth–telluride material was confirmed as an efficient and harmless material in thermoelectric applications by the results obtained from the density functional theory. The calculations were carried out using the FP-LAPW method with Wien2k code. This is the classic thermoelectric material used in refrigeration and thermoelectric generators due to its high Seebeck coefficient value and low thermal conductivity. Here Tin is replaced in parent SnTe by bismuth as various doping concentrations. The spin-orbit coupling was used in both electronic and thermoelectric properties calculations. Also we discussed mechanical properties of Sn(1–x)BixTe (x = 0, 0.125, 0.25, 0.5, 0.75, 0.875 and 1) materials. The result confirms that all the doped materials are ductile in nature and parent SnTe is of brittle nature. Here we have discussed the results on both spin-orbit coupling (SOC) and non-SOC calculations in thermoelectric properties. Changes occurred in band structure, and density of states according to SOC and non-SOC calculations were clearly explained. Also, the calculations of Seebeck coefficient, electrical conductivity with relaxation time, power factor, electronic thermal conductivity and figure of merit were made with SOC and without SOC over the temperature range of 300–1000 K. From the results, it was obtained that, within the SOC calculations, thermoelectric properties of the studied materials were enhanced at high temperature. [ABSTRACT FROM AUTHOR]

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Orbital anisotropy at interfaces in magnetic heterostructures has been key to pioneering spin–orbit‐related phenomena. However, modulating the interface's electronic structure to make it abnormally asymmetric has been challenging because of lack of appropriate methods. Here, the authors report that low‐energy proton irradiation achieves a strong level of inversion asymmetry and unusual strain at interfaces in [Co/Pd] superlattices through nondestructive, selective removal of oxygen from Co3O4/Pd superlattices during irradiation. Structural investigations corroborate that progressive reduction of Co3O4 into Co establishes pseudomorphic growth with sharp interfaces and atypically large tensile stress. The normal component of orbital to spin magnetic moment at the interface is the largest among those observed in layered Co systems, which is associated with giant orbital anisotropy theoretically confirmed, and resulting very large interfacial magnetic anisotropy is observed. All results attribute not only to giant orbital anisotropy but to enhanced interfacial spin–orbit coupling owing to the pseudomorphic nature at the interface. They are strongly supported by the observation of reversal of polarity of temperature‐dependent Anomalous Hall signal, a signature of Berry phase. This work suggests that establishing both giant orbital anisotropy and strong spin–orbit coupling at the interface is key to exploring spintronic devices with new functionalities. [ABSTRACT FROM AUTHOR]

The defected double perovskites, being non-toxic, stable, and capable to exhibit both spin-up (↑) and spin-down (↓) polarizations, are attractive for spintronic devices. In the present article, the role of 5 d -electrons of Os and Ir to control the magnetic characteristics of Rb 2 (Os/Ir)Cl/Br 6 is addressed. The structural and magnetic characteristics are investigated using PBEsol-mBJ functional, while thermoelectric behaviors are studied using BoltzTrap code. The computed tolerance factors (0.95/0.98, 0.94/0.96) and formation energies (−2.0/-1.65eV, −1.70/-1.10eV) confirm the structural and thermodynamic stabilities, respectively. The examination of band structures and density of states have revealed half-metallic ferromagnetic nature, which is further discussed in terms of double exchange model, exchange constants and exchange energies. The presented calculations indicate that underlying hybridization process, exchange energy, and crystal field energy induce ferromagnetism due to electron spin. Furthermore, thermal, and electrical conductivities, power factor, and Seebeck coefficients are computed and discussed to understand the thermoelectric applications. [ABSTRACT FROM AUTHOR]

Narrowband emissive organoboron emitters featuring the multi‐resonance (MR) effect have now become a critical material component for constructing high‐performance organic light‐emitting diodes (OLEDs) with pure emission colors. These MR organoboron emitters are capable of exhibiting high‐efficiency narrowband thermally activated delayed fluorescence (TADF) by allowing triplet‐to‐singlet reverse intersystem crossing (RISC). However, RISC involving spin‐flip exciton upconversion is generally the rate‐limiting step in the overall TADF; hence, a deeper understanding and precise control of the RISC dynamics are ongoing crucial challenges. Here, we introduce the first MR organoboron emitter (CzBSe) doped with a selenium atom, demonstrating a record‐high RISC rate exceeding 108 s−1, which is even higher than its fluorescence radiation rate. Furthermore, the spin‐flip upconversion process in CzBSe can be accelerated by factors of ≈20000 and ≈800, compared to those of its oxygen‐ and sulfur‐doped homologs (CzBO and CzBS), respectively. Unlike CzBO and CzBS, the photophysical rate‐limiting step in CzBSe is no longer RISC, but the fluorescence radiation process; this behavior is completely different from the conventional time‐delaying TADF limited by the slow RISC. Benefitting from its ultrafast exciton spin conversion ability, OLEDs incorporating CzBSe achieved a maximum external electroluminescence quantum efficiency as high as 23.9 %, accompanied by MR‐induced blue narrowband emission and significantly alleviated efficiency roll‐off features. [ABSTRACT FROM AUTHOR]

Thermally activated delayed fluorescence (TADF) is an upconversion photophysical process based on the population of a bright excited singlet state from an excited triplet via reverse intersystem crossing (rISC), which might be employed to overcome the statistical limitation of electron‐hole recombination in organic light‐emitting diodes. In this work, we describe the intricacies of TADF dynamics by means of a quantum master equation and through perturbative approaches to rate constants of internal conversion and ISC. Simulation of the time evolution from the lowest excited triplet in systems with small energy gaps allows to disentangle the role of different electronic states mediating the population of the singlet manifold and the importance of various rISC mechanisms. Energy gaps between charge transfer (CT) and local excitons (LE), and interstate (hyperfine, spin‐orbit and vibronic) couplings are key factors tuning the feasibility of rISC. Since in molecules LE/CT spin‐orbit coupling is, in general, larger than hyperfine interactions, the rISC rate is largely increased in those situations where either the direct or mediated triplet‐singlet interconversion between states of different character is energetically available. Interestingly, temperature dependence of rISC rate is stronger for the spin‐vibronic coupling mechanism than via hyperfine interaction. [ABSTRACT FROM AUTHOR]

We studied the emergence of the quantum spin Hall (QSH) states for the pseudo-gap (PG) phase of Bi2212 bilayer system, assumed to be D-density wave (DDW) ordered, starting with a strong Rashba spin-orbit coupling (SOC) armed, and the time reversal symmetry (TRS) complaint Bloch Hamiltonian. The presence of strong SOC gives rise to non-trivial, spin-momentum locked spin texture tunable by electric field. The emergence of quantum anomalous Hall effect with TRS broken Chiral DDW Hamiltonian of Das Sarma et al. is found to be possible. [ABSTRACT FROM AUTHOR]

Group IV graphene analogues such as stanene, plumbene, etc. have drawn attention because of their large spin–orbit coupling and thus being promising candidates for topological insulator. However, fabrication of these ultrathin monolayers is a daunting task. To reduce the difficulties of the fabrication of 2D topological insulators, bilayer materials with sizable nontrivial bandgaps can be a viable option. Chemically decorated bilayer stanene is a novel structure which has not been studied before. Herein, the topological characteristics of halogen‐decorated bilayer of stanene are studied and their topological nontriviality is confirmed by calculating the Z2 invariant. As the topological nontriviality can be preserved for these bilayers, these materials will have advantages over their monolayer counterparts in terms of fabrication difficulties. Halogen‐decorated stanene bilayers (except Br) are topologically nontrivial and their nontrivial nature is tunable by external strain. Hybrid functional (HSE06) has been employed to calculate the band structures of the materials at various strains. Also, the band structures of their zigzag nanoribbons have been analyzed. Lastly, the formation energy, quantum molecular dynamics, and phonon dispersion confirm their electronic and structural stability. The proposed material may speed up the fabrication of 2D topological insulators aiming future spintronic and high‐speed electronic devices. [ABSTRACT FROM AUTHOR]

Spin–orbit coupling (SOC), the interaction between spin and orbital angular momentum of electrons, is imperative to control magnetic properties of nonmagnet (NM)/ferromagnet (FM) heterostructures and design energy‐efficient and faster spin‐based devices. Here, femtosecond pulsed laser‐induced time‐resolved magneto‐optical Kerr effect magnetometry is employed to investigate magnetization dynamics in different NM/Co20Fe60B20 heterostructures, where the NM layer varies as Cu, Ta, W, Pt, Ta/Ru/Ta, and Si/SiO2 (no underlayer) that differ in SOC strength. It is observed that there is a systematic variation in ultrafast demagnetization time (τm), fast remagnetization time (τr), and Gilbert damping parameter (α) with the SOC strength of the underlayer and an inverse relationship between α and τm, τr is established due to the dominant contribution of spin current transport in ultrafast demagnetization and fast remagnetization processes. The spin pumping formalism estimates the effective spin‐mixing conductance (Geff) for different interfaces, which signifies that the high SOC strength of underlayers results in high Geff indicating more efficient transport of spin current through it. This study suggests that the SOC strength of the NM underlayer plays a significant role in controlling the ultrafast demagnetization process through interfacial spin current transport in a NM/FM heterostructure which can be beneficial for the development of ultrafast spintronics devices. [ABSTRACT FROM AUTHOR]

We report that the spin vector of photoelectrons emitted from an atomic layer Pb grown on a germanium substrate [Pb/Ge(111)] can be controlled using an electric field of light. The spin polarization of photoelectrons excited by a linearly polarized light is precisely investigated by spin- and angle-resolved photoemission spectroscopy. The spin polarization of the photoelectrons observed in the mirror plane reverses between p- and s-polarized lights. Considering the dipole transition selection rule, the surface state of Pb/Ge(111) is represented by a linear combination of symmetric and asymmetric orbital components coupled with spins in mutually opposite directions. The spin direction of the photoelectrons is different from that of the initial state when the electric field vector of linearly polarized light deviates from p- or s-polarization conditions. The quantum interference in the photoexcitation process can determine the direction of the spin vector of photoelectrons., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Japanese Society of Microscopy.)

The J eff ) with spin-orbit coupling (SOC) and crystal field splitting, offers a platform in the research of quantum materials. In this context, 4 U ) with spin-orbit coupling (SOC) and crystal field splitting, offers a platform in the research of quantum materials. In this context, 4 f rare-earth based materials offer a fertile playground. Here, strong experimental and theoretical evidences for a J eff = ½ state is established in a three-dimensional spin system NdVO 4 . Magnetic measurements show the signatures of a SOC driven J eff = ½ state along with the presence of antiferromagnetic (AFM) interaction between Nd 3+ moments, whereas, heat capacity reveals the presence of an AFM ordering around 0.8 K, within this state. An entropy of Rln2 (equivalent to J = ½) is released around 4 K which implies the presence of J eff = ½ state at low temperatures. Total energy calculations within the density functional theory (DFT) framework reflect the central role of SOC in driving the Nd 3+ ions to host such a state with AFM correlations between them, which is in agreement with experimental results. Further, DFT + SOC calculations with and without the inclusion of U , points that electron-electron correlations give rise to the insulating state making NdVO 4 a potential candidate for U -driven correlated Mott insulator., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

A fast reverse intersystem crossing (RISC) remains an ongoing pursuit for multiresonance (MR) emitters but faces formidable challenges, particularly for indolocarbazole (ICz) derived ones. Here, heavy-atom effect is introduced first to construct ICz-MR emitter using a sulfur-containing substitute, simultaneously enhancing both spin-orbit and spin-vibronic coupling to afford a fast RISC with a rate of 1.2 × 10 5  s -1 , nearly one order of magnitude higher than previous maximum values. The emitter also exhibits an extremely narrow deep-blue emission peaking at 456 nm with full-width at half-maxima of merely 12 nm and a photoluminescence quantum yield of 92%. Benefiting from its efficient triplet upconversion capability, this emitter achieves not only a high maximum external quantum efficiency (EQE) of 31.1% in organic light-emitting diodes but also greatly alleviates efficiency roll-off, affording record-high EQEs of 29.9% at 1000 cd m -2 and 18.7% at 5000 cd m -2 among devices with ICz-MR emitters., (© 2024 Wiley‐VCH GmbH.)

Spin-orbit coupling (SOC) has significant effects on the superconductivity and magnetism of transition metal dichalcogenides (TMDs) at the 2D limit. Although 2D TMD samples possess many exotic properties different from those of bulk samples, experimental characterization in this field is still limited, especially for magnetism. Recent studies have revealed that bulk misfit layer compounds (MLCs) with (LaSe) 1.14 (NbSe 2 ) n = 1,2 exhibit an Ising superconductivity similar to that of heavily electron-doped NbSe 2 monolayers. This offers an opportunity to study the effect of SOC on the magnetism of 2D TMDs. Here, the possible SOC effect in (LaSe) 1.14 (NbSe 2 ) is investigated by measuring nuclear magnetic resonance (NMR) and electrical transport. It is found that the LaSe layer not only functions as a charge reservoir for transferring electrons into the NbSe 2 layer but also remarkably influences the local electronic environment around the 93 Nb nuclei. More importantly, the significant SOC induces both a weak antilocalization (WAL) effect and anisotropic spin fluctuations in noncentrosymmetric NbSe 2 layers. The present work contributes to a deep understanding of the role of the SOC effect in 2D TMDs and supports MCLs as an intriguing platform for exploring exotic physical properties within the 2D limit., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

By means of highly accurate ab initio and dynamical calculations, we identify a suitable laser cooling candidate that contains a transition metal element, namely zinc monohydride (ZnH). The internally contracted multireference configuration interaction method is employed to compute the five lowest-lying Λ-S states of ZnH with the spin-orbit coupling effects included, and very good agreement is obtained between our calculated and experimental spectroscopic data. Our findings show that the position of crossing point of the A 2 Π and B 2 Σ + states of ZnH is above the v ' = 2 vibrational level of the A 2 Π state indicating that the crossings with higher electronic states will have no effect on laser cooling. Hence, we construct a feasible laser-cooling scheme for ZnH using five lasers based on the A 2 Π 1/2 → X 2 Σ + 1/2 transition, which features a large vibrational branching ratio R 00 (0.8458), a large number of scattered photons (9.8 × 10 3 ) and an extremely short radiative lifetime (64 ns). The present work demonstrates the importance of electronic state crossings and spin-orbit couplings in the study of molecular laser cooling., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Li, Fayyaz and Bian.)

1D charge transport offers great insight into strongly correlated physics, such as Luttinger liquids, electronic instabilities, and superconductivity. Although 1D charge transport is observed in nanomaterials and quantum wires, examples in bulk crystalline solids remain elusive. In this work, it is demonstrated that spin-orbit coupling (SOC) can act as a mechanism to induce quasi-1D charge transport in the Ln 3 MPn 5 (Ln = lanthanide; M = transition metal; Pn = Pnictide) family. From three example compounds, La 3 ZrSb 5 , La 3 ZrBi 5 , and Sm 3 ZrBi 5 , density functional theory calculations with SOC included show a quasi-1D Fermi surface in the bismuthide compounds, but an anisotropic 3D Fermi surface in the antimonide structure. By performing anisotropic charge transport measurements on La 3 ZrSb 5 , La 3 ZrBi 5 , and Sm 3 ZrBi 5 , it is demonstrated that SOC starkly affects their anisotropic resistivity ratios (ARR) at low temperatures, with an ARR of ≈4 in the antimonide compared to ≈9.5 and ≈22 (≈32 after magnetic ordering) in La 3 ZrBi 5 and Sm 3 ZrBi 5 , respectively. This report demonstrates the utility of spin-orbit coupling to induce quasi-low-dimensional Fermi surfaces in anisotropic crystal structures, and provides a template for examining other systems., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

Polarization and related spin properties are important characteristics of electromagnetic waves and their manipulation is crucial in almost all photonic applications. Magnetic materials are often used for controlling light polarization through the magneto-optical Kerr or Faraday effects. Recently, complex topological structures of the optical spin have been demonstrated in the evanescent light field, which in the presence of the spin–orbit coupling may form photonic skyrmions. Here, we investigate the optical spin–orbit coupling in the presence of magnetization and the interaction between photonic skyrmions and magnetic domains. We demonstrate that the magnetization is responsible for the modulation of the optical spin distribution, resulting in twisted Neel-type skyrmions. This effect can be used for the visualization of magnetic domain structure with both in plane and polar orientation of magnetization, and in turn for creation of complex optical spin distributions using magnetization patterns. The demonstrated interplay between photonic skyrmions and magneto-optical effects may also provide novel opportunities for investigation and manipulation of magnetic skyrmions using optical spin–orbit coupling.

Abstract Orbital anisotropy at interfaces in magnetic heterostructures has been key to pioneering spin–orbit‐related phenomena. However, modulating the interface's electronic structure to make it abnormally asymmetric has been challenging because of lack of appropriate methods. Here, the authors report that low‐energy proton irradiation achieves a strong level of inversion asymmetry and unusual strain at interfaces in [Co/Pd] superlattices through nondestructive, selective removal of oxygen from Co3O4/Pd superlattices during irradiation. Structural investigations corroborate that progressive reduction of Co3O4 into Co establishes pseudomorphic growth with sharp interfaces and atypically large tensile stress. The normal component of orbital to spin magnetic moment at the interface is the largest among those observed in layered Co systems, which is associated with giant orbital anisotropy theoretically confirmed, and resulting very large interfacial magnetic anisotropy is observed. All results attribute not only to giant orbital anisotropy but to enhanced interfacial spin–orbit coupling owing to the pseudomorphic nature at the interface. They are strongly supported by the observation of reversal of polarity of temperature‐dependent Anomalous Hall signal, a signature of Berry phase. This work suggests that establishing both giant orbital anisotropy and strong spin–orbit coupling at the interface is key to exploring spintronic devices with new functionalities.