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An exciton–polariton condensate is a hybrid light–matter state in the quantum fluid phase. The photonic component endows it with characters of spin, as represented by circular polarization. Spin-polarization can form stochastically for quasi-equilibrium exciton–polariton condensates at parallel momentum vector k|| ∼ 0 from bifurcation or deterministically for propagating condensates at k|| > 0 from the optical spin-Hall effect (OSHE). Here, we report deterministic spin-polarization in exciton–polariton condensates at k|| ∼ 0 in microcavities containing methylammonium lead bromide perovskite (CH3NH3PbBr3) single crystals under non-resonant and linearly polarized excitation. We observe two energetically split condensates with opposite circular polarizations and attribute this observation to the presence of strong birefringence, which introduces a large OSHE at k|| ∼ 0 and pins the condensates in a particular spin state. Such spin-polarized exciton–polariton condensates may serve not only as circularly polarized laser sources but also as effective alternatives to ultracold atom Bose–Einstein condensates in quantum simulators of many-body spin–orbit coupling processes. [ABSTRACT FROM AUTHOR]

The combined influence of spin–orbit coupling and spatial inversion asymmetry leads to an enhancement of electronic properties, including Rashba spin-splittings as well as spin Hall effect. Recent research has shown the possibility to create two-dimensional Janus materials with inherent structural asymmetry. In this work, the structural stability, piezoelectricity, electronic properties, and intrinsic spin Hall conductivity of quintuple-layer atomic Janus Sb2XSX' (X, X' = S, Se, Te; X ≠ X') monolayers are investigated using first-principles calculations within the framework of density functional theory. They demonstrate relatively high in-plane piezoelectric coefficients ( d 22) and also possess out-of-plane piezoelectric coefficients ( d 31), which is due to the breaking of inversion symmetry in the crystal structure with the space group P3m1. Large Rashba parameters are obtained in Janus Sb2XSX' monolayers, especially high for Sb 2 S 2 Te (1.62 eV Å) and Sb 2 SeSTe (1.33 eV Å) due to strong spin–orbit coupling. Moreover, Rashba-like spin-splitting is also observed in the edge-states as well, which is highest for Sb 2 SeSTe with 2.17 eV Å. Furthermore, Sb 2 S 2 Te and Sb 2 SeSTe monolayers reveal a significantly high Berry curvature (65.59 and 61.05 Bohr 2), spin Berry curvature (− 118.4 and − 120.6 Bohr 2), and spin Hall conductivity (1.8 and 1.6 e 2 /h). Our results suggest that Janus Sb 2 S 2 Te and Sb 2 SeSTe monolayers could be an excellent platform for multifunctional electronic applications. [ABSTRACT FROM AUTHOR]

The photonic spin Hall effect has attracted considerable attention for its potential applications in precision metrology and spin-based photonics. However, the spin-dependent transverse shift arising from this phenomenon is considerably weak and poses a challenge in terms of detection. Here, we present a novel technique to amplify the photonic spin Hall effect by exciting the optical Tamm states through an Au-distributed Bragg reflector. Our approach involves optimizing the thickness of the Au layer and the spacing layer, as well as adjusting the Fermi energy of graphene. The result is a remarkable transverse shift of up to 18 μm in the horizontal polarization state. Furthermore, we introduce graphene into the Au-distributed Bragg reflector to enable dynamic control of the photonic spin Hall effect by manipulating the Fermi energy of graphene. These findings represent an innovative platform for enhancing and actively controlling the photonic spin Hall effect with significant potential for spin-controlled optics. [ABSTRACT FROM AUTHOR]

The recent discovery of inherently stable two-dimensional (2D) transition-metal dichalcogenides (TMDs) provides a unique platform for spintronic devices. However, its efficacy for electric detection by spin Hall magnetoresistance (SMR) has not been established yet. In this work, we report on SMR in 2D TMDs/ferromagnet heterostructures, i.e., PtSe 2 /NiFe (Py), whose magnitude reaches the maximum with bilayer PtSe 2. Notably, the SMR value in bilayer PtSe 2 /Py heterostructures undergoes a sign change with increasing Py thickness. For thinner Py samples, the SMR rapidly decreases with increasing Py thickness, eventually changing from positive to negative. In the case of intermediate Py thicknesses, the SMR consistently exhibits negative behavior. However, for thicker Py samples, the negative SMR values gradually decrease. This complex behavior is attributed to the dominant and competing mechanisms that contribute to SMR, including the spin Hall effect (or Rashba-induced effect) and its inverse effect, the orbital Hall effect and its inverse effect, as well as interfacial spin–orbit-coupling-induced spin-current-to-charge-current conversion. These findings would expand the arsenal for advanced spintronic applications based on 2D TMDs. [ABSTRACT FROM AUTHOR]

We investigate the photonic spin Hall effect of a linearly polarized Gaussian beam reflected on the surface of twisted bilayer phosphorene. The photonic spin shift depends strongly on optical resonance behavior, which is determined by the twist angle. The magnified spin shift near the Brewster angle is sensitive to the twist angle and can be fitted by numerical models. In particular, the spin shifts in the terahertz region of frequency are well within the current experimental detection precision. Our findings suggest that the photonic spin Hall effect is promising for precise characterization of the optical property and the structure of twisted bilayer phosphorene. [ABSTRACT FROM AUTHOR]

Thin layers of ferromagnetic/non-magnetic bimetallic heterostructures have become the focal point of spintronics, primarily due to their capacity to convert spin to charge current, leveraging the spin- and inverse spin Hall effects. However, the interfacial properties and morphologies can significantly influence this conversion. Hence, we employed molecular dynamics calculations to model the construction of the Fe/Pt interface at various bilayer growth temperatures and Pt deposition rates. We then experimentally evaluated the modeling using x-ray methods to resolve the chemical and structural state of the interface. The calculations revealed moderate diffusive phenomena between the adjacent layers and an interfacial roughness of less than 1 nm, consistent with the experimental observations. In cases where plastic relaxation of the Fe/Pt interface is insufficient, lattice deformation is mitigated by a local pseudomorphic growth caused by transformation of the Pt crystal symmetry. Additionally, interfacial planar defects may emerge as a complementary stress-relieving mechanism to misfit dislocations. By combining the experimental and computational findings, we propose optimized growth conditions for an "ideal" Fe/Pt interface, which could serve as a useful tool to control the efficiency of spin-to-charge conversion. [ABSTRACT FROM AUTHOR]

In this work, we study the electronic properties of nanotubes with spin–orbit interaction that exhibit a spin Hall effect. Nanoribbons made of these materials are expected to have topologically protected states. The lack of edge states in a seamless tube eliminates the possibility of finding a topological edge state. The spin–orbit interaction breaks the degeneracy of Dirac's cones and eliminates the chance of finding a metal nanotube. As a consequence, this makes all nanotubes with spin–orbit interaction trivial band insulators. We focus our attention on two features. First, we study the energy band gap as a function of the diameter of the nanotubes. Then, we concentrate on controlling the bandgap of a nanotube by applying an external radial electric field. Finally, we discuss the possibility of using one of these tubes as a field-effect transistor. [ABSTRACT FROM AUTHOR]

Photonic spin Hall effect (PSHE) of the transmitted wave presents promising applications in photonic spintronic devices, including inter-chip optical circuitry and quantum computing devices. These applications can benefit from phenomena such as the photon tunneling effect, frustrated total internal reflection, and the resonant optical tunneling effect. However, the mechanisms for enhancing PSHE of the transmitted wave are limited. In this study, an alternative strategy is proposed, which involves the utilization of topological edge states to enhance PSHE without relying on the aforementioned means. To demonstrate this effect, a heterostructure is designed, comprising two one-dimensional photonic crystals (PhCs) and a monolayer graphene. By leveraging the topological edge state, a significant enhancement of PSHE in the transmitted wave is observed, surpassing several times the incident wavelength. Furthermore, it is shown that the enhanced PSHE can be controlled and fine-tuned by adjusting the Fermi energy of monolayer graphene and the repetition numbers of the two PhCs. The enhanced and controlled PSHE in this heterostructure introduces possibilities for the development of novel optical components, such as switches, filters, modulators, and sensors. [ABSTRACT FROM AUTHOR]

We study the W/Cu multilayers as a spin current source and the coherent spin–orbit torques in a Fe layer using the spin-torque ferromagnetic resonance (STFMR) technique. With increasing numbers of layers, the line shape of the STFMR signals changes from predominantly antisymmetric to predominantly symmetric. When using [W(0.5)/Cu(0.5)]5 as a spin current source, the symmetric amplitude increases by a factor of 5 compared to a single W layer. Simultaneously, the effective damping parameter also increases slightly due to enhanced spin pumping. Along with an increasing trend in the damping-like torque efficiency, this suggests that the extrinsic spin Hall effect is enhanced. Concurrently, the antisymmetric amplitude decreases significantly by a factor of 27, which indicates an increase in the field-like torque when multilayers are used as a spin current source. [ABSTRACT FROM AUTHOR]

The asymmetric photonic spin Hall effect (APSHE) induced by surface plasmon polaritons in a graphene-based structure is actively manipulated by external magnetic field and electric field. It is revealed that the spin-dependent splitting exhibits spatio-temporal asymmetric property due to the involvement of the anisotropic graphene. The peak of asymmetry degree in APSHE at the position of reflectance valley corresponds toward a smaller incident angle with the increase of magnetic field intensity or Fermi energy, which is attributed to the tunability of reflectance for the graphene-based structure. Based on the asymmetric splitting shift, a potential application is proposed for detecting low concentration gas molecules and the detection resolution can be dynamically tunable by changing the magnetic field intensity and Fermi energy. This study may provide a new reference in the fabrication of graphene-based plasmonic sensor devices. [ABSTRACT FROM AUTHOR]

In this work, intrinsic spin Hall conductivity of β‐W and its alloy with V has been theoretically studied by the combination of ab initio method with the tight binding method. Both two possible configurations of V in β‐W structure are fully considered and their total energy difference used to estimate the thermodynamic average SHC of alloy by using Maxwell‐Boltzmann distribution. It is found that due to the small total energy difference between two configurations, there is a significant contribution to the thermodynamic average SHC of the alloy from both configurations, which results in the average SHC of alloy being enhanced up to 12.3% compared with the pristine β‐W. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Ultrafast control of both electric and spin currents triggered by femtosecond laser pulse has attracted much attention due to future applications for broadband THz emitter as well as high‐speed spintronic devices. Optically generated spin current is converted to charge current via multiple spin‐charge conversion mechanisms, generating THz wave emission in magnetic multilayers. However, to date, quantitative and comparative investigation of THz emission originating from spin‐charge conversion mechanisms has not yet been fully explored. Here, direct and straightforward nondestructive probing to measure THz emission is provided at original Co/Pt and Co/Ta interfaces embedded in Pt/Co/Ta multilayers with polarization analysis of both optical pump and THz emission. These results allow a fundamental understanding of various spin‐charge conversion phenomena, which is a key basis for future spintronic THz source development. [ABSTRACT FROM AUTHOR]

This paper investigates the relationship among interlayer exchange coupling (IEC), Dzyaloshinskii–Moriya interaction (DMI), and multilevel magnetization switching within a Co/Pt/Co heterostructure, where varying Pt thicknesses enable control over the coupling strength. Employing Brillouin Light Scattering to quantify the effective DMI, we explore its potential role in magnetization dynamics and multilevel magnetization switching. Experimental findings show four distinct resistance states under an external magnetic field and spin Hall effect related spin current. We explain this phenomenon based on the asymmetry between Pt/Co and Co/Pt interfaces and the interlayer coupling, which, in turn, influences the DMI and subsequently impacts the magnetization dynamics. Numerical simulations, including macrospin, 1D domain wall, and simple spin wave models, further support the experimental observations of multilevel switching and help uncover the underlying mechanisms. Our proposed explanation, supported by magnetic domain observation using polar-magnetooptical Kerr microscopy, offers insights into both the spatial distribution of magnetization and its dynamics for different IECs, thereby shedding light on its interplay with DMI, which may lead to potential applications in storage devices. [ABSTRACT FROM AUTHOR]

Spintronic devices require materials that facilitate effective spin transport, generation, and detection. In this regard, graphene emerges as an ideal candidate for long‐distance spin transport owing to its minimal spin‐orbit coupling, which, however, limits its capacity for effective spin manipulation. This problem can be overcome by putting spin‐orbit coupling materials in close contact with graphene leading to spin‐orbit proximity and, consequently, efficient spin‐to‐charge conversion through mechanisms such as the spin Hall effect. Here, the gate‐dependent spin Hall effect in trilayer graphene proximitized with tin sulfide (SnS) is reported and quantified, a group‐IV monochalcogenide that has recently been predicted to be a viable alternative to transition‐metal dichalcogenides for inducing strong spin‐orbit coupling in graphene. The spin Hall angle exhibits a maximum around the charge neutrality point of graphene up to room temperature. The findings expand the library of materials that induce spin‐orbit coupling in graphene to a new class, group‐IV monochalcogenides, thereby highlighting the potential of 2D materials to pave the way for the development of innovative spin‐based devices and future technological applications. [ABSTRACT FROM AUTHOR]

Lead halide perovskites (LHPs) containing organic parts are emerging optoelectronic materials with a wide range of applications thanks to their high optical absorption, carrier mobility, and easy preparation methods. They possess spin-dependent properties, such as strong spin–orbit coupling (SOC), and are promising for spintronics. The Rashba effect in LHPs can be manipulated by a magnetic field and a polarized light field. Considering the surfaces and interfaces of LHPs, light polarization-dependent optoelectronics of LHPs has attracted attention, especially in terms of spin-dependent photocurrents (SDPs). Currently, there are intense efforts being made in the identification and separation of SDPs and spin-to-charge interconversion in LHP. Here, we provide a comprehensive review of second-order nonlinear photocurrents in LHP in regard to spintronics. First, a detailed background on Rashba SOC and its related effects (including the inverse Rashba–Edelstein effect) is given. Subsequently, nonlinear photo-induced effects leading to SDPs are presented. Then, SDPs due to the photo-induced inverse spin Hall effect and the circular photogalvanic effect, together with photocurrent due to the photon drag effect, are compared. This is followed by the main focus of nonlinear photocurrents in LHPs containing organic parts, starting from fundamentals related to spin-dependent optoelectronics. Finally, we conclude with a brief summary and future prospects. [ABSTRACT FROM AUTHOR]

In this paper, we have measured the magneto-optical spin Hall effect influenced by an arbitrary oriented magnetic field using CeDyAl thin films on Gd3Ga5O12 (GGG) substrates as reflective materials. Plots of the variation of the magneto-optic spin Hall effect (MOPSHE) with magnetic field strength, the hysteresis line, in three different unit-direction magnetic fields are simulated and experimentally measured. The comparison of the simulation results with the experiments allows the method of weak measurement to determine the MOPSHE under the influence of the magnetic field to be validated. MOPSHE under a three-dimensional magnetic field is measured and the measurement error is within 4 μ m. [ABSTRACT FROM AUTHOR]

The electronic structure of silicene supported by monolayer of different monochalcogenide MX (GaS, GaSe, GaTe and InSe) substrates has been investigated by first principle density functional theory. By calculating the formation energies and phonons, it has been seen that silicene supported by monolayer of MX remains stable. The systems retain their almost 2 D planner configurations with small buckling as that of the free standing silicene and also the Bader charge analysis shows that silicene hardly interacts with any of the MX substrates. The Dirac cone with a small gap (∼ 3 0 – 5 0   meV) has been observed in each of the cases. All the systems show quantum spin Hall effect and the quantum spin Hall conductivities have been estimated to be within the range ∼ 2 − 5 ℏ e S/cm, which are larger than that of the free standing silicene. Our calculations show that even if the systems have bulk band gaps but the edge states are conducting in nature. [ABSTRACT FROM AUTHOR]

Canted antiferromagnets offer great potential in fundamental research and for use in applications due to their unique properties. The presence of the Dzyaloshinskii–Moriya interaction (DMI) leads to the existence of a weak ferromagnetic moment at room temperature. We study both theoretically and experimentally microwave spin pumping by a quasi-ferromagnetic mode from a canted easy plane antiferromagnet with weak ferromagnetism FeBO3. The conversion of a microwave signal into a constant voltage is realized using the inverse spin Hall effect in an iron borate/heavy metal heterostructure. We use an additional bias magnetic field to selectively tune the resonance frequency of such a microwave detector over a wide range up to 43.5 GHz with a potential sensitivity near 2.5 µ V W−1. We confirm the pure spin current nature by changing the polarity of the detected via inverse spin Hall effect voltage by switching the direction of the bias magnetic field. We believe that our results will be useful for the development of highly tunable, portable and sensitive microwave antiferromagnet-based functional devices. [ABSTRACT FROM AUTHOR]

The thermo-spin conversion provides new concepts for further developing the green energy-harvesting technology because spin can be controlled with minimal energy in nanostructures. Through theoretical analysis of thermo-spin generation, transportation and conversion in ferromagnet/non-ferromagnet/heavy metal (FM/NM/HM) vertical structures, we found that the output transverse thermo-spin voltage is independent of the structure's width, but varies linearly with the structure's length. To validate our predictions, we fabricated the thermo-spin devices with a CoFeAl/Cu/Pt structure. Our results indicate that FM/NM/HM structures can be utilized to design flexible thermo-spin conversion devices. [ABSTRACT FROM AUTHOR]

Here, we report a photonic spin Hall effect (PSHE), i.e., splitting of opposite spin in a transverse direction using a multi-layered metallo-dielectric heterostructure by hybridization of a Tamm plasmon polariton and a surface plasmon polariton. The underlying mechanism of PSHE is also explained using the concept of superposition of normal and abnormal modes in the circular-polarization basis. It is revealed that the spin-dependent transverse shift for the proposed hybrid structure is enormously high owing to the transverse shift of ∼18 μm. The PSHE is found to be strongly dependent on the number of bi-layers of the structure and the analyte refractive index, which provides an additional degree of freedom for tailoring the device performance. Therefore, this study opens a pathway for developing next-generation photonic spin Hall devices in the fields of spin photonics, optical sensing, and optical communications. [ABSTRACT FROM AUTHOR]

We investigate the spin Hall effect in a single-layer graphene device with disorder and interface-induced spin–orbit coupling. Our graphene device is connected to four semi-infinite leads that are embedded in a Landauer–Büttiker setup for quantum transport. We show that the spin Hall angle of graphene devices exhibits mesoscopic fluctuations that are similar to metal devices. Furthermore, the product between the maximum spin Hall angle deviation and dimensionless longitudinal conductivity follows a universal relationship Θ s H × σ = 0.18. Finally, we compare the universal relation with recent experimental data and numerically exact real-space simulations from the tight-binding model. [ABSTRACT FROM AUTHOR]

We present a detailed investigation of spin pumping from full Heusler compound Co2FeSi (CFS) to single-layer two-dimensional (2D) transition metal dichalcogenide (TMD) MoS2 (molybdenum disulfide) excited by ferromagnetic resonance. Microwave-induced spin pumping has been identified by a significant enhancement of Gilbert damping in Si/SiO2/MoS2/CFS heterostructures as compared to bare Si/SiO2/CFS samples. The CFS thickness dependent spin mixing conductance indicates an efficient spin transparent interface of MoS2/CFS. In addition, the spin-to-charge conversion process has been quantified using inverse spin Hall effect (ISHE) measurements. In ISHE measurements, a highly symmetric Lorentzian DC voltage signal in Si/SiO2/MoS2/CFS heterostructures is observed in comparison with a highly asymmetric signal in bare Si/SiO2/CFS samples, establishing a clear sign of FMR induced spin pumping. The results in this work are expected to aid in the understanding of the spin angular momentum transfer phenomenon at the interface of the 2D TMDs/ferromagnet bilayer system. [ABSTRACT FROM AUTHOR]

Current flowing through heavy metals generates spin current by the spin Hall effect (SHE), and spin current exerts a torque on the adjacent magnetic layer, thereby switching the magnetization direction of the magnetic layer. Normally, an external magnetic field must be used to break symmetry in the response to the SHE torque, to realize deterministic switching. However, the presence of magnetic fields increases the difficulty in integrating spintronic devices with complementary metal-oxide-semiconductor. Thus, field-free spin–orbit torque switching has been a research hotspot. Here, symmetry-breaking has been realized by tilting the sample during the annealing process, resulting in a non-uniform diffusion of Ta atoms in the samples along the temperature gradient (x-direction), which was confirmed by transmission electron microscope mapping. As a result, the sample has demonstrated deterministic switching, in the absence of an external magnetic field, with a switching ratio of up to 88% and the critical current density of 1.5 × 107 A/cm2. Tilting annealing is a simple approach to achieve field-free switching. [ABSTRACT FROM AUTHOR]

This study presents an innovative refractive index (RI) sensor that measures glucose concentration by utilizing the photonic spin Hall effect (SHE) in a resonant optical tunneling effect (ROTE) structure. The ROTE structure consists of three InP layers with the high RI and two analyte layers (with a high‐low‐high‐low‐high RI distribution), in which glucose solution samples with the low RI are injected. By subjecting the InP layers to external bias‐assisted light, the photonic SHE can be flexibly manipulated, enabling the modulation of the sensing performance accordingly. It is found that the transverse shift of photonic SHE presents a large variation in response to the tiny change in glucose concentrations. By optimizing the parameters (i.e., intensity or wavelength) of bias light, the sensitivity of this sensor can reach as high as 735.7 µm RIU−1. Compared to traditional glucose sensors, this original work implements the novel photonic SHE with the superior sensing performance. Therefore, the proposed design shows promising potential for biomedical applications, such as medical diagnoses and drug discovery. [ABSTRACT FROM AUTHOR]

Magnetic Weyl semimetal shows intriguing properties in both fundamental physics and potential applications. However, the complex relationship between nonreciprocal transmission and magnetic field manipulation in magnetic Weyl semimetal systems has not been generally clarified and fully utilized. Here, a universal Chirality–Wavevector–Magnetic field (C‐K‐B) relation is established in the magnetic Weyl semimetal system, which completely describes the spin topological band and its intrinsic polarization output in full space orientation under an arbitrary magnetic vector. This relation can provide complete guidance for the device design of nonreciprocal spin manipulation. Coupling this nonreciprocal mechanism with the photonic spin Hall effect of the geometric phased metasurface, a magnetic Weyl semimetal metasurface is constructed in the terahertz (THz) range, The experiments demonstrate the flexible THz beam steerings in a broad spatial dispersion range of ±25–±55° with four different working modes by only altering the biased magnetic vectors. Moreover, all these beam steering processes are accompanied by nonreciprocal isolating transmission with the isolation ratio reaching 27 dB. This C‐K‐B relation and active nonreciprocal beam steering devices are expected to prompt magneto‐optical devices and systems combined with echo isolation function in beam scanning, wavelength division multiplexing, and spin multiplexing. [ABSTRACT FROM AUTHOR]

Topological Hall effect (THE), induced by the interaction of charge carriers with mesoscopic or microscopic noncoplanar spin structures, holds promising applications in the field of spintronics. In the present study, a giant THE of about 2 μΩ cm at room temperature is reported in a bulk spin gapless semiconducting Mn2CoAl cubic Heusler compound. Temperature‐dependent investigation of magneto‐transport data reveals that the Mn2CoAl has the large THE over a wide temperature range of 2–300 K. The alternating current (AC) susceptibility as a function of magnetic field exhibits a smooth and continuous response rather than any kink or anomaly, suggests that the observed THE in the Mn2CoAl compound results from the interaction of charge carriers with the microscopic noncoplanar spin texture. The observed THE as a function of temperature follows the same behavior as the magnetocrystalline anisotropy (MCA) of the cubic Mn2CoAl, indicating the competition of the MCA with ferromagnetic and antiferromagnetic exchange interactions as the origin of the noncoplanar spin texture and hence THE. Micromagnetic simulations further support the emergence of noncoplanar spin structure as a result of the competition between different energies. [ABSTRACT FROM AUTHOR]

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]

The utilization of spintronic terahertz (THz) emitters has a significant influence on broadband coherent spectroscopy and imaging at THz frequencies. By using femtosecond light to irradiate the spintronic heterostructures, spin currents from the ultrafast demagnetization effect can be transformed into charge currents through the inverse spin Hall effect, leading to the emission of THz waves. In this work, through the incorporation of sequential and inverse deposition of W‐Co20Fe60B20‐Pt heterostructure films, control is gained over the spin currents and THz waveforms, enabling it to achieve a 180° phase difference across a broad frequency spectrum while efficiently radiating THz waves. This, in turn, allows it to control the spatial phase of THz radiation. To test the device's capabilities, lithography‐based devices capable of focusing, producing vortexes, and dividing beams are manufactured. This investigation aims to advance the development of THz pulse sources while providing essential support for cutting‐edge technologies such as THz spectroscopy, high‐resolution imaging, and high‐speed communications. [ABSTRACT FROM AUTHOR]

Manipulating the polarization of spin waves highlights the potential of antiferromagnetic magnonics in encoding and handling magnon information with high fidelity. Here, we propose a flexible approach to mutually convert polarization states (i.e., Hadamard gate) by incorporating a topological degree of freedom, intrinsic orbital angular momentum (OAM), into twisted spin wave modes within synthetic antiferromagnetic nanodisks. The polarization states of spin waves and the implementation of magnonic logic operations can be electrically read out through combined spin pumping and inverse spin Hall effect, as demonstrated by numerical micromagnetic simulations for CoFeB-based synthetic antiferromagnets. Our findings present an exciting possibility of parallel magnonic computing utilizing topologically protected and magnetic damping-resistance OAM of twisted magnons. [ABSTRACT FROM AUTHOR]

In this study, we investigate the spin Hall effect in heterostructures of Bi0.85Sb0.15 (10 nm) topological insulator/Ru(Ti)/Ta/Co20Fe60B20/MgO with perpendicular magnetic anisotropy. By optimizing the Ru (Ti) interfacial layer thickness as well as deposition condition of BiSb, we achieve a large effective spin Hall angle of 6.0 ± 0.1 and relatively high electrical conductivity of 1.5 × 105 Ω−1 m−1 at room temperature. We, then, demonstrate spin–orbit torque-induced magnetization switching driven by a small threshold current density of 1 × 106 Acm−2. Benchmarking shows that the writing power consumption of our stack is 2–3 orders smaller than that of heavy metals. [ABSTRACT FROM AUTHOR]

Hybrid dynamic systems combine advantages from different subsystems for realizing information processing tasks in both classical and quantum domains. However, the lack of controlling knobs in tuning system parameters becomes a severe challenge in developing scalable, versatile hybrid systems for useful applications. Here, we report an on-chip microwave photon–magnon hybrid system where the dissipation rates and the coupling cooperativity can be electrically influenced by the spin Hall effect. Through magnon–photon coupling, the linewidths of the resonator photon mode and the hybridized magnon polariton modes are effectively changed by the spin injection into the magnetic wires from an applied direct current, which exhibit different trends in samples with low and high coupling strengths. Moreover, the linewidth modification by the spin Hall effect shows strong dependence on the detuning of the two subsystems, in contrast to the classical behavior of a standalone magnonic device. Our results point to a direction of realizing tunable, on-chip, scalable magnon-based hybrid dynamic systems, where spintronic effects provide useful control mechanisms. [ABSTRACT FROM AUTHOR]

Fast and robust measurement of the surface susceptibility is still in urgent need for investigation and application of atomically thin crystals. In this work, we propose an effective method to measure the surface susceptibility of single-layer graphene by detecting the photonic spin Hall effect in momentum space. At a graphene interface, the beam separations with different spin states contain an angular component due to the existence of surface susceptibility. By implementing a postselection with real weak value in our scheme, the contribution of the spatial spin-Hall shift is excluded and the angular one is amplified for detection. It is demonstrated that treating the angular shift as a pointer allows for a reliable determination of the surface susceptibility. Our method may pave a way for the optical parameter characterization of two-dimensional atomic crystals via angular metrology. [ABSTRACT FROM AUTHOR]

In this work, the spin pumping technique was employed to investigate the anomalous inverse spin Hall effect in BIG/NiO/Fe samples where BIG[ (Bi , Tm) 3 (Fe , Ga) 5 O 12 ] exhibits perpendicular magnetic anisotropy. Our results reveal an intriguing phenomenon: when the magnetization of both ferromagnetic layers is perpendicular to each other, a distinct spin-to-charge current conversion mechanism occurs. This conversion is intricately linked to the magnetization of the converting layer, spin polarization, and the spin current orientation. [ABSTRACT FROM AUTHOR]

We present a detailed investigation of various routes to optimize the power consumption of the spintronic-based devices for implementing rectified linear activation (ReLU) and max-pooling functions. We examine the influence of various spin Hall effect layers, and their input resistances on the power consumption of the ReLU-max pooling functions, we also access the impact of the thermal stability factor of the free-ferromagnet layer on the power consumption and accuracy of the device. The design for ReLU-max pooling relies on the continuous rotation of magnetization, which is accomplished by applying orthogonal spin current to the free-FM layer. We also demonstrate the non-trivial power-resistance relation, where the power consumption decreases with an increase in SHE resistance. We utilize the hybrid spintronic-CMOS simulation platform that combines Keldysh non-equilibrium Green's function (NEGF) with Landau-Lifshitz-Gilbert-Slonzewski (LLGS) equations and the HSPICE circuit simulator to evaluate our network. Our design takes 0.343 μW of power for ReLU emulation and 17.86 μW of power for ReLU-max pooling network implementation at a thermal stability factor of 4.58, all while maintaining reliable results. We validate the efficiency of our design by implementing a convolutional neural network that classifies the handwritten-MNIST and fashion-MNIST datasets. This implementation illustrates that the classification accuracies achieved are on par with those attained using the ideal software ReLU-max pooling functions, with an energy consumption of 167.31 pJ per sample. [ABSTRACT FROM AUTHOR]

In this work, a transverse spin-dependent shift of the horizontal photonic spin Hall effect at a fixed wavelength (0.6328 μm) is simulated for cancer cell detection based on refractive index, chemical potential, and electrical voltage variations applied to a plasmonic sensor with five layers (Ge20Ga5Sb10S65 chalcogenide prism, silver, gold, grapheme, and cancerous medium). When the conventional weak measurement is applied and when the chemical potential is increased from 0.3 eV to 8 eV, the chemical and voltage resolutions are 3.87 × 10–7 eV, 13.3327 μV for n5 = 1.38 RIU (cancerous skin cell), 5.17 × 10–7 eV, 17.7889 μV for n5 = 1.392 RIU (cancerous cervical cell), 4.95 × 10–7 eV, 17.0249 μV for n5 = 1.390 RIU (cancerous blood cell), and 5.50 × 10–7 eV, 18.9514 μV for n5 = 1.395 RIU (cancerous adrenal gland cell), respectively. The values of the chemical and voltage resolutions (1.90 × 10–7 eV, 6.5560 μV for n5 = 1.36 RIU and normal skin cell) are better than for the case when the spin Hall effect is not applied (0.00513 eV, 0.1766 V). The voltage resolutions calculated with the conventional weak measurement method are comparable or considerably better to the best experimental values which can resolve voltage differences as small as 15 μV. [ABSTRACT FROM AUTHOR]

Although the spin‐controlled vortex generation and photonic spin‐Hall effect of spin‐flipped abnormal mode have been widely studied recently, the traditional method based on the metasurface is difficult to fabricate, and the efficiency of the spin‐flipped abnormal mode is rather low due to process errors and intrinsic material loss. Here, a new method is proposed based on the insights into the topological singularity and special Bragger reflections resonant (BRR) mode of one‐dimensional (1D) finite photonic crystals (PhCs) with anisotropic material to realize nearly perfect (100%) spin‐conversion efficiency. For a finite 1D PhC with cell number N, there are 3N complete spin‐conversion (CSC) and complete spin‐maintained (CSM) channels. Two mechanisms of these CSC and CSM channels are revealed. The working bandwidths and the angular ranges of these CSC and CSM are also studied. Based on these theoretical findings, multi‐angles and multi‐frequencies perfect spin‐conversion (‐maintained) devices can be designed. At last, these theoretical results are confirmed by the numerical experiments based on finite‐difference time‐domain (FDTD) methods. This work paves the way to exploring the topological properties and polarization control of PhCs made of anisotropic dielectrics and provides a prospective method for the design of multi‐channels spin optical devices. [ABSTRACT FROM AUTHOR]

Half-Heusler alloy topological semimetal YPtBi is a promising candidate for an efficient spin current source in spin–orbit torque (SOT) devices thanks to its large spin Hall angle θSH (>1) and high thermal stability (600 °C). However, the spin Hall effect has been studied so far in high quality YPtBi(111) thin films deposited on c-Sapphire substrates. In this work, we study the SOT performance of sputtered YPtBi films deposited on SiO2/Si substrates. We realized YPtBi(110) thin films with large θSH of 1.3 at a relatively high conductivity of 1.4 × 105 Ω−1 m−1. The spin Hall conductivity of YPtBi(110) is even better than those of YPtBi(111) thin films deposited on c-Sapphire substrates, despite the lower crystal quality. Our results pave the way for using YPtBi in integrated SOT devices on Si substrates. [ABSTRACT FROM AUTHOR]

The finite Berry curvature in topological materials can induce many subtle phenomena, such as the anomalous Hall effect (AHE), spin Hall effect (SHE), anomalous Nernst effect (ANE), non-linear Hall effect (NLHE) and bulk photovoltaic effects. To explore these novel physics as well as their connection and coupling, a precise and effective model should be developed. Here, we propose such a versatile model—a 3D triangular lattice with alternating hopping parameters, which can yield various topological phases, including kagome bands, triply degenerate fermions, double Weyl semimetals and so on. We reveal that this special lattice can present unconventional transport due to its unique topological surface states and the aforementioned topological phenomena, such as AHE, ANE, NLHE and the topological photocurrent effect. In addition, we also provide a number of material candidates that have been synthesized experimentally with this lattice, and discuss two materials, including a non-magnetic triangular system for SHE, NLHE and the shift current, and a ferromagnetic triangular lattice for AHE and ANE. Our work provides an excellent platform, including both the model and materials, for the study of Berry-curvature-related physics. [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]

In this contribution, by combining the nanocomposite with distributed Bragg reflector, a simple multilayer structure to enhance the photonic spin Hall effect (PSHE) via optical Tamm state (OTS) for both horizontal (H) and vertical (V) polarized lights is presented. The structural parameters of nanocomposite layer (e.g., thickness and filling factor) have a significant influence on PSHE. The maximal spin shifts of 16.2 and 17.8 μm can be achieved for H and V polarized lights, respectively, which are attributed to strong excitation of OTS. Moreover, the spin shift is extremely sensitive to the refractive index changes of sensing medium, and a gas sensor with superior sensing performance is theoretically proposed for both H and V polarized beams. These findings provide an effective method to enhance the PSHE for both H and V polarized lights and therefore open an opportunity for developing PSHE refractive index sensors. [ABSTRACT FROM AUTHOR]

The enhanced photonic spin Hall effect was previously possible only for the horizontal polarization (H-polarized) in plasmonic systems. The wave-guiding surface plasmonic resonance (SPR) effect is used to report a giant photonic spin Hall effect (G-PSHE) of reflected light for horizontal and vertical polarized waves. This novel work investigated the polarization-manipulated G-PSHE in the modified Kretschmann configuration with an additional glass dielectric thin wave-guiding layer. The ultrathin gold layer and an additional dielectric wave-guiding layer are responsible for achieving millimeter-scale (more than 2 mm to submillimeter) G-PSHE. With this novel approach, polarization manipulation is achieved by employing wave-guiding and the SPR effect. Using a finite element method based simulation study, the impact of an additional thin dielectric wave-guiding layer on G-PSHE is investigated. This study enables the potential application of both horizontal and vertical polarization-based quantum devices and sensors for which light spin plays a pivotal role. [ABSTRACT FROM AUTHOR]

We demonstrate the concept of Berry phase monopole engineering of the spin Hall effect in non-centrosymmetric silicide TaSi2. We show that while the effective damping-like spin–orbit torque (SOT) efficiency θ DL eff of TaSi2 is nearly unchanged from 62 to 288 K (−0.049 to −0.069), θ DL eff suddenly increases at high temperatures and becomes nearly double (−0.12) at 346 K. The corresponding intrinsic spin Hall conductivity σ DL eff significantly increases at high temperatures, which can be attributed to the increasing contribution from the four degenerate points near the Fermi level via thermal excitation. Our results provide a strategy to enhance θ DL eff at high temperatures via Berry phase monopole engineering and pave the way for SOT spintronic devices working at high temperatures. [ABSTRACT FROM AUTHOR]

The discovery of spin–orbit torques (SOTs) generated through the spin Hall or Rashba effects provides an alternative write approach for magnetic random-access memory (MRAM), igniting the development of spin orbitronics in recent years. Quantitative characterization of SOTs highly relies on the SOT-driven ferromagnetic resonance (ST-FMR), where a modulated microwave current is used to generate ac SOTs and the modulation frequency is usually less than 100 kHz (the limit of conventional lock-in amplifiers). Here, we have investigated the SOT of typical SOT material/ferromagnet bilayers in an extended modulation-frequency range, up to MHz, by developing the ST-FMR measurement. Remarkably, we found that the measured SOTs are enhanced about three times in the MHz range, which cannot be explained according to the present SOT theory. We attribute the enhancement of SOT to additional magnon excitations due to phonon–magnon coupling, which is also reflected in the slight changes of resonant field and linewidth in the acquired ST-FMR spectra, corresponding to the modifications of effective magnetization and damping constant, respectively. Our results indicate that the write current of SOT-MRAM may be reduced with the assistance of phonon–magnon coupling. [ABSTRACT FROM AUTHOR]

The interplay between chirality and topology nurtures many exotic electronic properties. For instance, topological chiral semimetals display multifold chiral fermions that manifest nontrivial topological charge and spin texture. They are an ideal playground for exploring chirality-driven exotic physical phenomena. In this work, we reveal a monopole-like orbital-momentum locking texture on the three-dimensional Fermi surfaces of topological chiral semimetals with B20 structures (e.g., RhSi and PdGa). This orbital texture enables a large orbital Hall effect (OHE) and a giant orbital magnetoelectric (OME) effect in the presence of current flow. Different enantiomers exhibit the same OHE which can be converted to the spin Hall effect by spin-orbit coupling in materials. In contrast, the OME effect is chirality-dependent and much larger than its spin counterpart. Our work reveals the crucial role of orbital texture for understanding OHE and OME effects in topological chiral semimetals and paves the path for applications in orbitronics, spintronics, and enantiomer recognition. [ABSTRACT FROM AUTHOR]

Antiferromagnetic L12-Mn3Ir combines outstanding spin-transport properties with magnons in the terahertz (THz) frequency range. However, the THz radiation emitted by ultrafast spin-to-charge conversion via the inverse spin Hall effect remains unexplored. In this study, we measured the THz emission and transmission of a Permalloy/(111)-oriented L12-Mn3Ir multilayer by THz time-domain spectroscopy. The spin Hall angle was determined to be approximately constant at 0.035 within a frequency range of 0.3–2.2 THz, in comparison with the THz spectroscopy of a Permalloy/Pt multilayer. Our results not only demonstrate the potential of L12-Mn3Ir as a spintronic THz emitter but also provide insights into the THz spin transport properties of L12-Mn3Ir. [ABSTRACT FROM AUTHOR]

Utilizing micromagnetic modeling, we have explained the unprobed characteristics of 360° full cycle in-plane magnetization rotation and the resulting propagation of a magnetization wave along a ferromagnet nanowire. The magnetization wave, which is generated by setting off spin oscillation at one end of a ferromagnetic strip, propagates till the end of the wire. A perpendicular spin torque oscillator (STO) could generate magnetization rotation at one end of the ferromagnetic strip that is also part of the STO. Our results demonstrate that the oscillation frequency of the spins along the wire maintains excellent fidelity while the spatial wavelength of the magnetic wave increases. The driving mechanism behind the propagation of the wave is found to be exchange-springs, which enables the propagation of the wave without the need for a 'carrier' force, such as spin-transfer torque (STT) or spin Hall effect (SHE). Furthermore, we demonstrate that the gradient of the exchange energy drives the magnetic wave forward, while the in and out of plane anisotropy fields govern the shape of spin oscillation trajectories along the wire. Additionally, we show that stopping the oscillation at the STO end causes the wave to cease propagation after relaxation, and altering the STO rotational chirality leads to merging and annihilating domain walls of opposite winding numbers. [ABSTRACT FROM AUTHOR]

The photonic spin Hall effect (PSHE) has been intensively studied and widely applied, especially in spin photonics. In this paper, we present the analysis of PSHE in the Plexcitonic system. The signature of the Plexciton is studied by implanting an organic semiconductor layer over the plasmon active metal. We report a high spin-dependent transverse shift of ∼ 60 μm, which is ∼200-fold larger than that of the pure Plasmonic counterpart. The underlying mechanism of PSHE is explained in the circular-polarization basis using the concept of superposition of abnormal and normal modes. It is observed that the transverse shift is highly sensitive to the alterations in the environmental refractive indices leading to its application as a highly sensitive PSHE-based refractometer, with a high sensitivity of 81°/RIU. We believe these results may open pathways for modulating the PSHE and developing nanophotonic applications such as advanced sensors and next-generation optical devices. [ABSTRACT FROM AUTHOR]

The weak-value-amplification (WVA) effect, which is also called weak measurement, has been developed extensively in various sensing systems. Here, we report the actual realization of the WVA effect in spin-exchange relaxation-free atomic magnetometer system, wherein the slight separation of transverse momentum of the probe light is amplified by introducing orthogonal pre- and post-selection states. A differential detector is used to obtain the transverse position of the probe light accurately in real time. The weak coupling of the magneto-optical interaction with atoms will be reflected in the differential signal. The WVA effect is observed and demonstrated directly and a high sensitivity of 8 fT / H z is achieved. Also, we obtain the stable and distinct simulated magnetocardiography signal through our system. The present successful implementation of this probe method paves the way for further technical noise suppression and sensitivity improvement of quantum sensors. [ABSTRACT FROM AUTHOR]

Bismuth (Bi) has the strongest spin‐orbit coupling among non‐radioactive elements and is thus a promising material for efficient charge‐to‐spin conversion. However, previous electrical detections have reported controversial results for the conversion efficiency. In this study, an optical detection of a spin‐orbit torque is reported in a Bi/CoFeB bilayer with a polycrystalline texture of (012) and (003). Taking advantage of the optical detection, spin‐orbit torque is accurately separated from the Oersted field and achieves a giant damping‐like torque efficiency of +0.5, verifying efficient charge‐to‐spin conversion. This study also demonstrates a field‐like torque efficiency of −0.1. For the mechanism of the charge‐to‐spin conversion, the bulk spin Hall effect and the interface Rashba‐Edelstein effect are considered. [ABSTRACT FROM AUTHOR]