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We study theoretically the supercurrent and the superconducting diode effect (SDE) in a structure comprising parallel-coupled double quantum dots (DQDs) sandwiched between two superconductor leads in the presence of a magnetic flux. The influence of the Rashba spin–orbit interaction (RSOI), which induces a spin-dependent phase factor in the dot–superconductor coupling strength, is taken into account by adopting the nonequilibrium Green's function technique. This RSOI-induced phase factor serves as a driving force for the supercurrent in addition to the usual superconducting phase difference, and it leads to the system's left/right asymmetry. Correspondingly, the magnitude of the positive and negative critical currents become different from each other: the so-called SDE. Our results show that the period, magnitude, and direction of the supercurrents depend strongly on the RSOI-induced phase factor, dots' energy levels, interdot coupling strengths, and the magnetic flux. In the absence of magnetic flux, the diode efficiency is negative and may approach − 2 , which indicates the perfect diode effect with only negative flowing supercurrent in the absence of a positive one. Interestingly enough, both the sign and magnitude of the diode efficiency can be efficiently adjusted with the help of magnetic flux, the dots' energy levels and the interdot coupling strength and thus provide a controllable SDE by rich means, such as gate voltage or host materials of the system. [ABSTRACT FROM AUTHOR]

In this paper, a comparative analysis and numerical simulation of operation of two types of amplitude binary gratings (conventional and fork), both in the focal plane and near-field diffraction under illumination by mode beams with different polarization states, were performed. The simulation of the field formation in the focal plane was performed using the Richards–Wolf formalism. The diffraction calculation in the near-field diffraction was performed based on the FDTD method, considering the 3D structure of optical elements. The possibility of multiplying the incident beam in different diffraction orders of binary gratings and the polarization transformation associated with spin–orbit interaction at tight focusing were shown. In this case, various polarization transformations were formed in ±1 diffraction orders of the fork grating due to different signs of the introduced vortex-like phase singularity. The obtained results can be useful for the laser processing of materials and surface structuring. [ABSTRACT FROM AUTHOR]

On the occasion of the 50th anniversary of point-contact spectroscopy, we review and extend some of our recent studies on the effects of spin-orbit interactions located at an electric point contact connecting two bulk superconductors. In particular, we study the effects on the Josephson tunneling of Cooper pairs between the superconductors. We demonstrate that such tunneling forces the electronic spin to fluctuate quantum mechanically, transforming a BCS condensate into a quantum superposition of singlet and triplet pairs. The relative prevalence of those pairs can be controlled electrostatically and mechanically. The singlet pairs contribute to the Josephson charge current flowing through the point contact but not to the Josephson spin current injected into the superconductors. The spin-polarized pairs contribute to the injected Josephson spin current but not to the superconducting charge flow. These results allow for new functionalities of spin-active Josephson junctions. [ABSTRACT FROM AUTHOR]

We investigate theoretically the Casimir interaction between two parallel two-dimensional electron gases (2DEGs) with Rashba and Dresselhaus spin-orbit interactions (SOIs), based on the quantum field theory. We derive an analytical expression for the polarization tensor and obtain the solution to the motion equation of the electromagnetic (EM) field. We calculate the Casimir-Lifshitz torque (CLT) between two parallel 2DEGs with Rashba and Dresselhaus SOIs, which can be tuned by changing the relative strength between two SOIs. The anisotropic Casimir energy between 2DEGs caused by the interplay between the SOIs of 2DEGs offers a new origin of CLT and a new type of optoelectronic device. [ABSTRACT FROM AUTHOR]

Well-developed α clusters are known to exist in light N=Z nuclei, and their properties are reasonably well described with modern nuclear structure theories. However, 'modestly' developed clusters in medium to heavy nuclei remain little understood, both theoretically and experimentally. Extension of the focus to include modestly developed clusters leads us to a concept of 'generalized clusters' and 'cluster ubiquitousness'. The former includes clusters more weakly bound than an α cluster, such as deuteron, triton and He3 , and even clusters partially broken owing to nuclear medium effects. The latter means the existence of clusters in any nuclei, where cluster development was not previously discussed. Effects of the tensor and the spin–orbit interactions on the coexistence of clusters with independent nucleons are discussed using recent nuclear theoretical models. A mixture of the clusters with shell-like components plays an essential role in the synthesis of elements in the universe and the origin of life, together with an α decay. It is also pointed out that clustering in heavy nuclei may accelerate fission and fusion processes. Future experimental plans using cluster knockout reactions, which have the potential to extract information of 'generalized clusters' in a variety of nuclei including stable and unstable nuclei, are also discussed. This article is part of the theme issue 'The liminal position of Nuclear Physics: from hadrons to neutron stars'. [ABSTRACT FROM AUTHOR]

In this paper, we propose a method for resonant optical excitation of ortho states of two-electron donors in silicon, direct transitions to which from the ground state are extremely suppressed in case of a weak spin-orbit coupling. Excitation is proposed to be carried out using the points of anti-crossing of ortho and para states under conditions of uniaxial stress of the crystal. In these points the states cannot be unambiguously assigned to any group of states with a certain spin, as a result of which the optical transition becomes allowed. The structure of the energy levels of two-electron impurities is such that the excitation of such state almost unambiguously leads to the population of the underlying ortho-type state, which is expected to be very long-lived in the case of weak spin-orbit coupling. In the present work, theoretical estimates of the cross sections for optical transitions in the vicinity of the level anticrossing point as a function of strain for strong and weak spin-orbit coupling are made. [ABSTRACT FROM AUTHOR]

We study theoretically the supercurrent and the superconducting diode effect (SDE) in a structure comprising parallel-coupled double quantum dots (DQDs) sandwiched between two superconductor leads in the presence of a magnetic flux. The influence of the Rashba spin–orbit interaction (RSOI), which induces a spin-dependent phase factor in the dot–superconductor coupling strength, is taken into account by adopting the nonequilibrium Green’s function technique. This RSOI-induced phase factor serves as a driving force for the supercurrent in addition to the usual superconducting phase difference, and it leads to the system’s left/right asymmetry. Correspondingly, the magnitude of the positive and negative critical currents become different from each other: the so-called SDE. Our results show that the period, magnitude, and direction of the supercurrents depend strongly on the RSOI-induced phase factor, dots’ energy levels, interdot coupling strengths, and the magnetic flux. In the absence of magnetic flux, the diode efficiency is negative and may approach −2, which indicates the perfect diode effect with only negative flowing supercurrent in the absence of a positive one. Interestingly enough, both the sign and magnitude of the diode efficiency can be efficiently adjusted with the help of magnetic flux, the dots’ energy levels and the interdot coupling strength and thus provide a controllable SDE by rich means, such as gate voltage or host materials of the system.

In this paper, a comparative analysis and numerical simulation of operation of two types of amplitude binary gratings (conventional and fork), both in the focal plane and near-field diffraction under illumination by mode beams with different polarization states, were performed. The simulation of the field formation in the focal plane was performed using the Richards–Wolf formalism. The diffraction calculation in the near-field diffraction was performed based on the FDTD method, considering the 3D structure of optical elements. The possibility of multiplying the incident beam in different diffraction orders of binary gratings and the polarization transformation associated with spin–orbit interaction at tight focusing were shown. In this case, various polarization transformations were formed in ±1 diffraction orders of the fork grating due to different signs of the introduced vortex-like phase singularity. The obtained results can be useful for the laser processing of materials and surface structuring.

In this paper, we theoretically investigated the effect of the polycrystalline structure of metal samples on the magnitude of the spin Hall effect. The equation for the dynamics of the averaged over the crystallite momentum of the collectivized conduction electron in the crystalline field of a homogeneous and isotropic polycrystalline metal is obtained. Averaging the obtained equation over all randomly oriented crystallites resulted in an expression for the electric field of the spin Hall effect. It significantly depends on the form of the single-electron atomic radial wave function and on the Hall coefficient. The coefficients of the spin Hall effect for some metals of 3rd–6th periods are calculated. It is shown that the results for nonmagnetic d- and f-metals within the measurement error are consistent with the experimental data. The best match is observed for Pt, α -W, β -W, Pd, Nb, Ag, Mo, Cu and Al. A discrepancy of less than 20% was obtained for Au, Ti, Mn. For the considered rare-earth metals (Lu, Ho, Dy, Gd) only for paramagnetic Lu the correspondence of calculation results and experimental data is obtained. For Ho, Dy, and Gd, which exhibit ferromagnetic and antiferromagnetic states at low temperatures, the discrepancy is more than 35%. Based on the obtained results, the limitations of the developed approach are formulated. [ABSTRACT FROM AUTHOR]

This paper presents the results of experimental studies of the cross section of the interfaces of the SrIrO3/La0.7Sr0.3MnO3 and Pt/La0.7Sr0.3MnO3, heterostructures, in which, upon excitation of ferromagnetic resonance in a La0.7Sr0.3MnO3 film, a spin current arises that flows through the interface in structure. Epitaxial growth of thin films of strontium iridate SrIrO3 and manganite La0.7Sr0.3MnO3 on a (110)NdGaO3 single-crystal substrate was carried out using magnetron sputtering at a high temperature in a mixture of argon and oxygen gases. The spin mixing conductance, which determines the amplitude of the spin current and generally has real Re g↑↓ and imaginary Im g↑↓ parts, was determined from the frequency dependence of the FMR spectrum of the La0.7Sr0.3MnO3 film and the heterostructures. It is shown that the Im g↑↓ quantity can play an important role in determining the spin Hall angle (θSH) from the angular dependence of the spin magnetoresistance. For the SrIrO3/La0.7Sr0.3MnO3 heterostructures, θSH turns out to be significantly higher (almost an order of magnitude) than that for the Pt/La0.7Sr0.3MnO3 heterostructure. [ABSTRACT FROM AUTHOR]

The results of studies of magnetoresistance for GaAs filamentous crystals doped with tellurium admixture to a concentration of 2·1017 сm−3, in the temperature range 4.2–60 K and in the magnetic field ranges 0–14 T are presented. The GaAs filamentary crystal magnetoresistance has shown a sharp positive jump at a low magnetic field (up to 0.2 T) at a temperature near 4.2 K, while at higher magnetic field inductions linear behavior of magnetoresistance occurs. The low field magnetoresistance is discussed in the framework of weak localization of charge carriers due to their spin-orbit exchange interaction. The high-field linear magnetoresistance is connected with electron-electron interaction. [ABSTRACT FROM AUTHOR]

Spin–orbit coupling and nonparaxiality effects during the propagation of vortex vector light beams in a cylindrical graded-index waveguide are investigated by solving the full three-component field Maxwell's equations. Symmetry-breaking effects for left- and right-handed circularly polarized vortex light beams propagating in a rotationally symmetric graded-index optical fiber are considered. The mode-group delay in a graded-index fiber due to spin–orbit interaction is demonstrated. A scheme for observing the temporal spin Hall effect is proposed. It is shown that the relative delay times between vortex pulses of opposite circular polarizations of the order of 10 ps/km can be observed in graded-index fibers for high-order topological charges. [ABSTRACT FROM AUTHOR]

Using the linear combination operator method and variational technique improved by Tokuda, we obtain the expression of the effective mass of a strong coupled polaron in an anisotropic quantum dot. Due to the spin–orbit interaction, the effective mass of the polaron splits into two branches. The dependence of effective mass on temperature, electron–phonon coupling strength, transverse and longitudinal confinement lengths, and velocity is discussed by numerical calculation. The theoretical results indicate that the effective mass of the polaron is an increasing function of temperature and electron–phonon coupling strength, but a decreasing function of transverse confinement length, longitudinal confinement length, and velocity. The absolute value of spin splitting effective mass increases with the increase of temperature and spin–orbit coupling parameter, but decreases with the increase of transverse confinement length, longitudinal confinement length, and velocity. Due to the heavy hole characteristic, the spin splitting effective mass is negative. [ABSTRACT FROM AUTHOR]

The current work focuses on investigating how various external and structural factors can affect the electronic structure and optical properties of a GaAs/Ga1−xAlxAs quantum ring. Specifically, we have studied the effects of spin–orbit interaction (SOI), pressure, temperature, and dimensions on the energy levels, dipole transition matrix elements (DTMEs), susceptibilities, optical absorption coefficients (OACs), refractive index changes (RICs), and group velocity of the quantum ring. These results show that the ground state energy of the system increases with the concentration of aluminum, while increasing temperature and ring size leads to a decrease in DTMEs due to a decrease in wave function overlap. We have also found that the presence of Rashba SOI, pressure, temperature, as well as the ring’s size dominate the electronic structure and subsequently affect the OACs and RICs of the system. A significant enhancement of the OACs can be witnessed when the Rashba coefficient and ring size are enlarged. Furthermore, the results represent a red shift with enhanced Rashba coefficient and relaxation time, whereas the growing ring size results in a blue shift in Optical sensitivities. Finally, we have analyzed the dependence of the group velocity of probe light pulses on the ring's size, photon frequency, and incident optical intensity. Our findings suggest that by controlling these parameters appropriately, it may be possible to achieve effective control of light speed, which could have interesting applications in electro-optical quantum communication networks. Overall, this work sheds light on the potential applications of these findings in the design and construction of spin-based devices and may offer new avenues for further research in this field. [ABSTRACT FROM AUTHOR]

An electron transport was investigated both in Sr2IrO4 thin films and in Josephson heterostructures with Sr2IrO4 barrier. The band gap in Sr2IrO4 varied in wide range of 15–250 meV which depends on deposition conditions of thin films, or on nature of interfaces between the barrier and superconducting electrodes. [ABSTRACT FROM AUTHOR]

The transport properties of niobium films and strips fabricated on Y3Fe5O12 single-crystal films with the (111) and (100) orientations are studied in a wide temperature range from 300 to 4 K. It is shown that a decrease in the temperature of the superconducting transition and its broadening are more significant for the (111) orientation of the films, despite the fact that numerous magnetic-domain walls are localized under the niobium strips and should enhance superconductivity. It is shown that the dependence of the niobium resistance on the direction of magnetization and current is observed only in narrow and thin niobium strips and disappears as they thicken. Rotation of the in-plane magnetic field makes it possible to effectively switch the resistance of such structures in the region of an extended superconducting transition. A scheme for creating a diode effect on niobium strips is proposed and implemented. [ABSTRACT FROM AUTHOR]

Multidimensional manipulation of photonic spin Hall effect (PSHE) has attracted considerable interest due to its potential in a wide variety of spin-based applications. Plenty of research efforts have been devoted to transverse or longitudinal spin-dependent splitting; however, the splitting pattern that can self-rotate in a three-dimensional (3-D) space appears to be missing in literature. In this paper, we introduce a novel 3-D rotational PSHE, which can be realized and tuned using well-designed Pancharatnam–Berry phase metasurfaces. To demonstrate this phenomenon, we first show that when a single dielectric metasurface is used, the lobe-structured spin-splitting patterns on the transverse planes rotate and evolve along the propagation path. Then, we present that under two cascaded metasurfaces, the rotation angle of the splitting patterns are tunable by adjusting the relative rotation angle between the two metasurfaces. Finally, we manifest that the lobe number of the two spin-dependent splitting patterns can be independently controlled once we introduce a dynamic phase, which produces an asymmetrical rotational PSHE. The demonstrated phenomena can be used to achieve active manipulation of spin photons in multiple dimensions, and the developed device might find potential applications in various areas, e.g., optical microscopy.

Hall effect of light is a result of symmetry breaking in spin and/or orbital angular momentum (OAM) possessing optical system and is caused by e.g. refractive index gradient/interface between media or focusing of a spatially asymmetrical beam, similar to the electric field breaking the symmetry in spin Hall effect for electrons. The angular momentum (AM) conservation law in the ensuing asymmetric system dictates redistribution of spin and orbital angular momentum, and is manifested in spin-orbit, orbit-orbit, and orbit-spin conversions and reorganization, i.e. spin-orbit and orbit-orbit interaction. This AM restructuring in turn requires shifts of the barycenter of the electric field of light. In the present study we show, both analytically and by numerical simulation, how different electric field components are displaced upon tight focusing of an asymmetric light beam having OAM and spin. The relation between field components shifts and the AM components shifts/redistribution is presented too. Moreover, we experimentally demonstrate, for the first time, to the best of our knowledge, the spin-orbit Hall effect of light upon tight focusing in free space. This is achieved using azopolymers as a media detecting longitudinal or z component of the electrical field of light. These findings elucidate the Hall effect of light and may broaden the spectrum of its applications.

We study the transport properties of a two-dimensional electron system with an essential spin-orbit interaction under topological phase transition due to changing in-plane magnetic field. We have analyzed the contribution of diagonal and off-diagonal components of density matrix with respect to number of spin zone in the high-frequency conductivity. Analytical formulas for the conductivity tensor have been obtained. A numerical analysis giving full enough representation about the dependence of the conductivity on frequency and magnetic field is presented. We have shown that the contribution of the off-diagonal elements of density matrix is the greater than the higher the frequency of the alternating electromagnetic field. It has been established that for magnetic field value at which the minimum electron energy of upper spin zone exceeds the Fermi energy, the conductivity as a function of magnetic field change in discrete step. [ABSTRACT FROM AUTHOR]

Within the scalar-relativistic and full relativistic approximation, ab initio calculations of the electronic structure for all singlet and triplet states of the KRb molecule converging to the first two excited dissociation thresholds were performed. The adiabatic interatomic potentials and spin-orbit electronic matrix elements derived within of the framework of "a" and "c" Hund's coupling case as a function of the inter-nuclear distance have allowed the asymmetry puzzle of the fine structure Ω = 0+/–, 1, 2-splitting experimentally observed for vibrational levels of the triplet d3ΠΩ state of KRb. [ABSTRACT FROM AUTHOR]

To investigate electronic states at the interface between surfaces that exhibit unique spin-split band dispersions is an important step in the development of a new materials that can be used to spintronics device. Antimony (Sb) and bismuth (Bi) are interesting targets for studying the nature of peculiar spin properties due to spin-orbit interactions. In this study, we fabricated the Sb ultrathin films on Bi substrate. The surface structure and electronic states of Sb/Bi heterostructure was confirmed by the low-energy electron diffraction measurement and angle-resolved photoemission spectroscopy, respectively. For 2 and 3 BL Sb film on Bi substrate, we observed a "V"-shaped electronic band, which is significantly different from the electronic state of Bi thin film and freestanding Sb ultrathin film. We conclude that this band dispersion is caused by the tensile lattice strain of Sb ultrathin film and the hybridization effect of the wavefunction with the Bi substrate. [ABSTRACT FROM AUTHOR]

We analyze a ballistic electron transport through a corrugated (rippled) graphene system with a curvature-induced spin–orbit interaction. The corrugated system is connected from both sides to two flat graphene sheets. The rippled structure unit is modeled by upward and downward curved surfaces. The cooperative effect of N units connected together (the superlattice) on the transmission of electrons that incident at the arbitrary angles on the superlattice is considered. The set of optimal angles and corresponding numbers of N units that yield the robust spin inverter phenomenon are found. [ABSTRACT FROM AUTHOR]

Symmetry of the icosahedron group is a basic principle producing the analytical description of the fullerene by means of the theory of molecular orbitals. Further development of the fullerene model requires consideration of the half-integer statistics of the electron states. Double group of the icosahedron describes both statistics cases, but we use only fermions case, in other words, the spinor representation of the icosahedron group. In this representation, it is possible to remove restriction defining the parity of the wave function coordinate part and to build a table of characters for arbitrary meaning of the total momentum. Symmetry of the icosahedron produces algebraic structure of the residue ring on the modulo 5, when using momentum projection on chosen axis. If the momentum projection equals both ±5/2 the states come into one representation. If the momentum projection by absolute value is higher 5/2, the wave function occupies state with several entangled spinor. [ABSTRACT FROM AUTHOR]

Manipulating angular momentum of light relies on the change of geometric phase in anisotropic nanostructures or optical interface phenomena. Spin–orbit interactions demonstrated in normal incidence at a planar isotropic interface are conditioned by Brewster reflection, limited to the light beam with a single radial frequency in the k‐space. This study demonstrates a geometric (Pancharatnam–Berry) phase that overcomes Brewster angle limitations providing high variability in the modulation of light reflected from a planar isotropic interface. The examined geometric phase stems from the reflection anisotropy imitating the structural anisotropy of photoaligned liquid crystals and photonic metasurfaces. Using a geometric‐phase modulation of tightly focused light reflected from a glass slab, three modes of spin to orbital angular momentum conversion are demonstrated. The discovered reflective spin–orbit interaction allows for design of a double‐helix focusing sensor to be used in microscopy imaging for precise depth measurements (accuracy 109 nm and precision 7 nm in the range of 8 µm). Experiments with a focused astigmatic beam prove that a glass plate can perform very complex modulation of the geometric phase using illumination structuring. The results thus provide the foundation for the design of low‐cost geometric‐phase systems relying on the space‐variant reflection anisotropy. [ABSTRACT FROM AUTHOR]

In this work, we have performed the calculation of the structural, electronic and optical properties of a number of ordered structures of the InP1 – xBix alloys. To study the ternary InP1 – xBix alloys, we have considered four ordered structure. For x = 0.5, we have investigated two arrangements: CuAu–I-like and Chalcopyrite. However, for x = 0.25 and x = 0.75, we have used two other arrangements: Famatinite and Luzonite. We have shown that incorporation of Bi into InP matrix introduces an increase of the lattice constant and variation of the bond lengths In–P and In–Bi. We found a strong reduction of the band gap energy by 47 meV/%Bi accompanied by a strong increase in spin-orbit splitting energy Δso (spin-orbit interaction energy) with increasing Bi composition. We have shown that the Δso exceeds the energy band gap for composition of Bi about 18% (Δso > Eg). Finally, we have calculated the variation of the optical properties of InP1–xBix compounds, such as the dielectric function, refractive index and absorption coefficient versus Bi compositions. This work provides important insights on the InP1–xBix alloys purposing efficient approaches to widen its working region for optoelectronic and spintronic applications. [ABSTRACT FROM AUTHOR]

In this review paper, we study normal and anomalous Hall effects for two-dimensional degenerate electron gas in ultraclean electronic channels. The general approach of a semiclassical description using a density matrix is demonstrated. An analysis of the transition from the hydrodynamic regime to the diffusion regime is presented for normal and anomalous contributions in the Hall field and a discussion of the transition from the ballistic regime to the diffusion regime is presented. The sign changing of the Hall voltage for transitions from hydrodynamic and ballistic regimes to diffusion for various magnetic fields was discussed. [ABSTRACT FROM AUTHOR]

The anomalous Hall effect is theoretically studied in the transition from the diffusion regime to the hydrodynamic regime for two-dimensional degenerate electronic systems. The length of interparticle collisions is considered to be much less than the width of the electronic channel, and the length of electron momentum relaxation is arbitrary. All the main mechanisms of the anomalous Hall effect were taken into account: anomalous velocity, wave packet shift during scattering on impurities, and asymmetric scattering from defects. The main attention is paid to the analysis of contributions to the Hall field and voltage from semiballistic regions near the edges of the sample, the width of which is on the order of the relaxation length of the second angular harmonic of the electron distribution function. It is shown that these contributions always make parametrically small contributions to the difference in the anomalous Hall voltage at the edges of the sample. [ABSTRACT FROM AUTHOR]

We have theoretically studied the transport properties of the SIsN S O F structure consisting of thick (S) and thin (s) films of superconductor, an insulator layer (I), a thin film of normal metal with spin–orbit interaction (SOI) (N S O ), and a monodomain ferromagnetic layer (F). The interplay between superconductivity, ferromagnetism, and spin–orbit interaction allows the critical current of this Josephson junction to be smoothly varied over a wide range by rotating the magnetization direction in the single F-layer. We have studied the amplitude of the spin valve effect and found the optimal ranges of parameters. [ABSTRACT FROM AUTHOR]

Temporal metamaterials, based on time-varying constitutive properties, offer new exciting possibilities for advanced field manipulations. In this study, we explore the capabilities of anisotropic temporal slabs, which rely on abrupt changes in time from isotropic to anisotropic response (and vice versa). Our findings show that these platforms can effectively manipulate the wave-spin dimension, allowing for a range of intriguing spin-controlled photonic operations. We demonstrate these capabilities through examples of spin-dependent analog computing and spin–orbit interaction effects for vortex generation. These results provide new insights into the field of temporal metamaterials, and suggest potential applications in communications, optical processing and quantum technologies. [ABSTRACT FROM AUTHOR]

The formation of spin levels upon torsional deformation of nonchiral (n, n) carbon nanotubes has been theoretically studied. In the absence of mechanical deformation, nanotubes have inversion symmetry and a metallic band structure with a spin-degenerate state near the Fermi level. The twisting deformation breaks the inversion symmetry, so that the tube becomes chiral. As a result, due to the Rashba effect, the degeneracy of the levels is completely lifted and spin gaps are formed between the bands of predominantly α and β types. [ABSTRACT FROM AUTHOR]

Osmium compounds with the Os 5d 4 electron configuration and an octahedral environment of neighboring atoms attract much attention due to the influence of the spin-orbit interaction on the appearance of magnetic properties in materials. X-ray absorption near edge structure (XANES) spectroscopy makes it possible to obtain information about the value of the spin–orbit interaction from measuring the intensity ratio of lines near the absorption edges. The influence of the spin–orbit interaction on the Os L2,3-edge XANES spectra of osmium compounds having an octahedral environment of halogen atoms is studied. Two types of systems are investigated, namely, isolated osmium clusters in complex compounds and the OsCl4 compound containing Os polymer chains bridged by Cl atoms. Magnetic-susceptibility measurements show a nonmagnetic ground state and Van Vleck paramagnetism in the case of isolated clusters and a nonzero magnetic moment over the entire temperature range in OsCl4. As a result of measurements of the XANES spectra, high values of the line intensity ratio are obtained near the Os L3/L2 absorption edges, which is associated with the strong effect of the spin-orbit interaction on the electronic structure. The theoretical analysis of the XANES spectra of Os compounds with different ligands and outer-sphere cations shows that the electronic structure and magnetic properties depend on the spin–orbit interaction, the crystal-field splitting, the electron-pairing energy, and noncubic distortions of the Os environment. [ABSTRACT FROM AUTHOR]

The spin-orbit interaction is quite small compared to electrostatic forces in atoms. Nevertheless, this small interaction can have large consequences. Several examples of the importance of the spin-orbit force in atomic photoionization are presented and explained. [ABSTRACT FROM AUTHOR]

In their last article [Phys. Lett. A 2021, 389, 127091], the authors have extended the k⋅p approach by considering crossings with the spin–orbit interaction (SOI) up to the second order and studied the spin texture and Berry phase of the heavy‐mass holes (HHs) confined in the SiGe 2D quantum well system. HHs cause quasi‐degeneracy via the intersub‐band interaction (ISI) working as Dirac‐like singularity, leading to the energy‐dependent Berry phase "quantized" by π. This π quantization is understandable by counting the number of quasi‐degenerate points in the Brillouin zone alongside recognizing the sign of the Berry curvature there. Herein, the remaining holes of the light‐mass holes (LHs) and separate holes (SHs) are studied. The spin textures and the Berry curvatures and phases are explored comprehensively, focusing on the competition between the Rashba and Dresselhaus SOIs via ISI. Comparisons with HHs elucidate that LHs and SHs cause similar quasi‐degeneracy through ISI, functioning as the Dirac‐like singularity. As such, the Berry phase is quantized by π, confirming the validity of the counting model irrespective of hole type. In some peculiar cases, HHs and LHs cause a possible sign inversion in the Berry phase, leading to zero Berry phase against temperature. [ABSTRACT FROM AUTHOR]

Within the framework of effective mass theory, we investigate the effects of spin–orbit interaction (SOI) and Zeeman splitting on the electronic properties of an electron confined in GaAs single quantum rings. Energies and envelope wavefunctions in the system are determined by solving the Schrödinger equation via the finite element method. First, we consider an inversely quadratic model potential to describe electron confining profiles in a single quantum ring. The study also analyzes the influence of applied electric and magnetic fields. Solutions for eigenstates are then used to evaluate the linear inter-state light absorption coefficient through the corresponding resonant transition energies and electric dipole matrix moment elements, assuming circular polarization for the incident radiation. Results show that both SOI effects and Zeeman splitting reduce the absorption intensity for the considered transitions compared to the case when these interactions are absent. In addition, the magnitude and position of the resonant peaks have non-monotonic behavior with external magnetic fields. Secondly, we investigate the electronic and optical properties of the electron confined in the quantum ring with a topological defect in the structure; the results show that the crossings in the energy curves as a function of the magnetic field are eliminated, and, therefore, an improvement in transition energies occurs. In addition, the dipole matrix moments present a non-oscillatory behavior compared to the case when a topological defect is not considered. [ABSTRACT FROM AUTHOR]

Recently, we directly observed the out-of-plane Dresselhaus spin–orbit (SO) interaction field and extracted the SO coefficient β from InGaAs (110) quantum wells (QWs). However, the extracted β was much larger than that of the (001) QWs, which yielded an in-plane Dresselhaus SO field. In this study, we perform Monte-Carlo simulations and reproduce the results of time-resolved and spatiotemporally resolved Kerr rotation measurements in InGaAs (110) QWs. The results conclusively show that InGaAs (110) QWs have a strong out-of-plane Dresselhaus SO field as compared with (001) QWs. [ABSTRACT FROM AUTHOR]

As one of the main approaches to implement phase gradient in metasurfaces, Pancharatnam-Berry (PB) phase originated from the spin–orbit interaction (SOI) of light has attracted enormous interest during the past several decades. Different from classical PB phase in linear optics that equals to twice the rotational angle of anisotropic elements for half wave plate distance and circular polarization, the recently proposed generalized PB phase indicates that phase gradient equals to multiple times the rotation angle could be achieved by high-order symmetry metallic meta atoms. Here, we show that the generalized PB phase can also be implemented in all-dielectric metasurfaces with higher efficiency than their metallic counterparts. Besides, by merging generalized PB phase and propagation phase, several functional devices are designed that the symmetric performance of PB phase can be decoupled. Moreover, a detailed comparison between meta atoms with C2, C3, and C6 rotational symmetries is conducted to illustrate the difference between classical and generalized PB phase. These results may further supplement the concept of generalized PB phase and could find many applications in optics and photonics..

Magnetic textures, such as skyrmions and domain walls, engender rich transport phenomena, including anomalous Hall effect and nonlinear response. In this work, we discuss an anomalous Hall effect proportional to the net magnetic monopole charge and dependent on the skyrmion helicity that occurs by a skew scattering in a noncentrosymmetric two-dimensional magnet. This mechanism, which arises from the spin–orbit interaction (SOI), gives rise to a finite anomalous Hall effect in a ferromagnetic domain wall whose spins rotate in the xy plane despite no out-of-plane magnetic moment. We show that the presence and absence of the monopole contribution is related to crystal symmetry, which gives a guideline for finding candidate materials beyond the Rashba model. The results demonstrate the rich features arising from the interplay of SOI and magnetic textures, and their potential for detecting various magnetic textures in micrometer devices.

Under an applied electric field, certain non-centrosymmetric materials with broken time-reversal symmetry may exhibit non-reciprocal transport behavior in which the charge and spin currents contain components that are second order in the electric field. In this study, we investigate the second-order spin accumulation and charge and spin responses in the LaAlO _3 /SrTiO _3 (LaO/STO) system with magnetic dopants under the influence of linear and cubic Rashba spin–orbit coupling (RSOC) terms. We explain the physical origin of the second-order response and perform a symmetry analysis of the first- and second-order responses for different dopant magnetization directions relative to the applied electric field. We then numerically solve the Boltzmann transport equation by extending the approach of Schliemann and Loss (2003 Phys. Rev. B 68 165311) to higher orders in the electric field. We show that the sign of the second-order responses can be switched by varying the magnetization direction of the magnetic dopants or relative strengths of the two cubic RSOC terms and explain these trends by considering the Fermi surfaces of the respective systems. These findings provide insights into the interplay of multiple SOC effects in the LaO/STO system and how the resulting first- and second-order charge and spin responses can be engineered by exploiting the symmetries of the system.

Spin–orbit coupling and nonparaxiality effects during the propagation of vortex vector light beams in a cylindrical graded-index waveguide are investigated by solving the full three-component field Maxwell’s equations. Symmetry-breaking effects for left- and right-handed circularly polarized vortex light beams propagating in a rotationally symmetric graded-index optical fiber are considered. The mode-group delay in a graded-index fiber due to spin–orbit interaction is demonstrated. A scheme for observing the temporal spin Hall effect is proposed. It is shown that the relative delay times between vortex pulses of opposite circular polarizations of the order of 10 ps/km can be observed in graded-index fibers for high-order topological charges.

A theory of spin and charge transport in bounded metallic magnets has been constructed, which takes into account the effects of spin-orbit scattering of conduction electrons by crystal lattice defects. The theory can be used to describe the spin Hall effect and the anomalous Hall effect and can serve as a basis for describing the phenomena of spin-orbitronics. Phenomenological boundary conditions for the charge and spin fluxes at the interface between two different metals have been formulated, on the basis of which the injection of a pure spin current into a helimagnet, which arises in a normal metal as a manifestation of the spin Hall effect, is described. The existence of an "effect of chiral polarization of a pure spin current" is predicted, which consists in the appearance in a helimagnet of a longitudinally polarized pure spin current and a longitudinal component of the nonequilibrium electron magnetization, depending on the chirality of the helimagnet helix, upon injection of a transversely polarized spin current from a normal metal. [ABSTRACT FROM AUTHOR]

The spin Hall effect of light (SHEL) is the microscopic splitting of light into two circular polarizations at the optical interface along the perpendicular direction. With the advent of metamaterials/metasurfaces and their fast‐developing applications, the SHEL has been garnering significant scientific interest. Here, the principle and recent developments in SHEL research is reviewed. A theoretical description of the SHEL is provided, including the formalism and general techniques. Also, recent studies on and applications of the SHEL are extensively reviewed, including the enhancement of the spin Hall shift and efficiency, implementation of dynamic tunability, elimination of polarization dependence, and precision measurements. The review is concluded with a discussion on the future direction and prospects of the SHEL. [ABSTRACT FROM AUTHOR]

In the samples of nonmagnetic Al, Pt, and W metals of an asymmetric shape, which causes a nonequilibrium distribution of charge carriers, the transverse spin contributions of the spin-orbit interaction to the Hall and Nernst-Ettingshausen effects were studied by direct electric measurement. It is found a difference in the behavior of the spin contributions of thermal diffusion and electric nature in a magnetic field. The dependence of this behavior on the band structure that controls the profiles of spin magnetization, which is established at the edges of the sample by the accumulation of spins, is shown. An oscillographic visualization of the spin Hall effect on alternating current was carried out. [ABSTRACT FROM AUTHOR]

Spin-dependent electron tunneling in InAs/GaAs double-barrier heterostructures was theoretically studied using the matrix method. The effects of Dresselhaus spin–orbit interaction, in-plane wave vector, magnetic field, the magnitude of an electric field, and negative field on its spin-transport were discussed. The Dresselhaus spin–orbit interaction enhances the spin polarization and energy between spin resonances. The in-plane wave vector shifts the resonance of polarization, and the increasing in-plane wave vector shifts the resonance to a higher value on the energy scale. The increasing magnetic field enhances the Zeeman splitting and causes enhanced polarization. The spin splitting was achieved due to the tunable magnitude of the electric field, and the negative electric field highly influences the spin transport properties. [ABSTRACT FROM AUTHOR]

We theoretically investigated the proximity effect in SN S O F and SF'F structures consisting of a superconductor (S), a normal metal (N S O ), and ferromagnetic (F',F) thin films with spin–orbit interaction (SOI) in the N S O layer. We show that a normal layer with spin–orbit interaction effectively suppresses triplet correlations generated in a ferromagnetic layer. Due to this effect, the critical temperature of the superconducting layer in the SN S O F multilayer turns out to be higher than in a similar multilayer without spin–orbit interaction in the N layer. Moreover, in the presence of a mixed type of spin–orbit interaction involving the Rashba and Dresselhaus components, the SN S O F structure is a spin valve, whose critical temperature is determined by the direction of the magnetization vector in the F layer. We calculated the control characteristics of the SN S O F spin valve and compared them with those available in traditional SF'F devices with two ferromagnetic layers. We concluded that SN S O F structures with one controlled F layer provide solid advantages over the broadly considered SF'F spin valves, paving the way for high-performance storage components for superconducting electronics. [ABSTRACT FROM AUTHOR]

The current state of research on spin-orbit interaction in cofactor-free oxidases and dioxygenases during oxygen activation is considered. The spin activation of triplet oxygen during combustion and respiration is analyzed in comparison with the reactions of flavin-containing enzymes, as well as important cofactor-independent dioxygenases. The mechanism of the triplet-singlet transition in glucose oxidase and a number of dioxygenases, including the RuBisCo oxygenase pathway and chirality-induced spin selectivity, is considered. [ABSTRACT FROM AUTHOR]

This approach presents an investigation into the optical phenomena of squeezing and phase in ultracold boson atoms confined within an engineered faulty crystal. The analysis encompasses the impact of spin–orbit interaction and Zeeman field mechanisms, resulting in a substantial enhancement of sensitivity to these phenomena. An investigation of the phenomena is based on the Pancharatnam theory and the language of information entropy. The proposed approach offers a flexible and efficient means to manipulate the dynamics of atomic internal states. Challenges arising from crystal dissipation are addressed, and their influence on the observed phenomena is discussed. Additionally, an analytical solution of the Liouville equation is provided, accurately describing the behavior of the defective crystal. The findings of this study contribute to a deeper understanding of atom dynamics and provide a foundation for utilizing and manipulating geometric phases in quantum technologies. [ABSTRACT FROM AUTHOR]