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The effect of the Rashba spin-orbit interaction on the shot noise, spin/valley polarization in 8- Pmmn borophene-based superlattice are studied theoretically, by applying the transfer-matrix approach. The spin-dependent transmission probability can be easily controlled by the number of superlattice barriers, the strength of the Rashba, and the incident electron angle. The Fano factor without spin rotation as well as with spin rotation shows an oscillatory pattern versus the strength of the Rashba, and the oscillatory behavior becomes more pronounced as the number of barriers increases. Also, the Fano factor shows a strong dependence on the superlattice direction and number of barriers. The spin and valley polarizations can be easily controlled by the number of barriers and the direction of superlattice. Our findings in this work could provide useful for valleytronics/spintronics systems based on the 8- Pmmn borophene. [ABSTRACT FROM AUTHOR]

[Display omitted] • We study conductance and polarization in borophene magnetic junctions, theoretically. • The transmission probability can be is zero for most angles of incident electron. • Spin/valley polarization can be easily changed by the external magnetic field. • An 8- Pmmn borophene magnetic junctions can be used as an effective spin filter. • Full valley polarization can be achieved in an 8- Pmmn borophene magnetic junctions. Conductance, spin and valley polarizations through 8- Pmmn borophene barriers in the presence of external Rashba spin–orbit interaction (RSOI) and magnetic field are investigated theoretically. The spin-dependent conductance shows a strong dependence on the direction of the 8- Pmmn borophene barriers, the strength of RSOI and value of the magnetic field strength. For two barriers unlike to one barrier, the spin-dependent conductance exhibits a prominent oscillatory behavior. For the parallel configuration, the dependence of conductance on the magnetic field is more than for the antiparallel configuration. Transmission probability without and with spin rotation decreases drastically with the increase in the value of the magnetic field, so that for sufficiently large magnetic fields, the transmission probability is zero for most electron incidence angles. The size and direction of the spin and valley polarization can be tuned by the strength of RSOI, direction of the 8- Pmmn borophene barriers, size of the magnetic field and type of parallel or antiparallel configuration. In certain conditions, full valley polarization can be achieved in the proposed structure. [ABSTRACT FROM AUTHOR]

• We explore 2D systems with a type of spin-polarized nodal loop that are robust under SOC and characteristic an hourglass type dispersion. • γ -structure VCl 2 , which bridges hourglass loop materials and spintronics, exhibits many unique properties including large spin polarization and robust topological properties. • Most importantly, hourglass loop is intrinsic and do not require any external conditions in experiments such as strain, magnetic field, or electric field. Hourglass loop in two-dimensional (2D) systems is typically vulnerable against spin–orbit coupling (SOC). Here, we explore 2D systems with a type of spin-polarized nodal loop that is robust under SOC and characteristic of an hourglass-type dispersion. Through first-principles calculations, we identify the monolayer VCl 2 materials as a realistic material platform to realize an hourglass loop. There exist three phases, all of which are dynamically stable. For the γ -structure, as a new single spin hourglass loop material. It shows semiconducting and gapless properties in spin down and spin up channels, respectively. Moreover, it always exhibits an hourglass loop property in the absence and presence of SOC. It indicates that the hourglass has strong against SOC. Our work suggests a realistic material platform for investigating the novel physics associated with band crossings in 2D systems. [ABSTRACT FROM AUTHOR]

Trilayer graphene exhibits valley-protected gapless states when the stacking order changes from ABC to CBA and a gate voltage is applied to outer layers. Some of these states survive strong distortions of the trilayer. For example, they persist when the outer layers are partially devoid yielding a system of two trilayers of different stacking order connected by a strip of a single graphene layer. Here we investigate how these states respond to another perturbation, i.e., the presence of magnetic defects, which we model as π -vacancies. We show that the gap states hybridize with the defect states and strongly spin-split. More importantly, it is demonstrated that by changing the gate voltage value one can change the spin density of the gap states and the corresponding currents at the Fermi level. [ABSTRACT FROM AUTHOR]

The spin-interdependent transport features for phosphorene superlattice, containing spin-flip and spin polarization are described under a constant electric field and extrinsic Rashba spin-orbit interaction utilizing the transfer matrix method. Our findings demonstrated the number of barriers at this structure acts the prominent role at the spin polarization and transmission probability, that can be applied in modeling optimum spintronic apparatus. Interestingly, the best outcomes for the transmission probability and spin polarization transpired in the five obstacles. Furthermore, an incoming electron with spin-up (down) can be transferred as an electron with spin-down (up) by adjusting the bias voltage and Rashba strength. Our findings can be utilized to create new nanostructures and maximize the performance of spintronic systems based on phosphorene nanoribbons. • The spin- independent transport features for a phosphorene superlattice, containing spin-flip and spin polarization have been studied under a constant electric field and extrinsic Rashba spin-orbit interaction utilizing the transfer matrix method. • The barriers number in the superlattice structure plays a dominant role in the spin polarization and transmission probability, that can be applied in modeling optimum spintronic apparatus. • By tuning the strength of external Rashba strength, and the bias voltage, it is possible to accurately control the conductance properties of the system and achieve high conductance which can be used in nano-electronic circuits and semiconductor devices. • The results show that by controlling the Rashba strength and the bias voltage, Spin Flip occurs. [ABSTRACT FROM AUTHOR]

We investigate the production of spin-polarized currents in corrugated graphene nanoribbons. Such corrugations are modeled as multiple regions with Rashba spin-orbit interactions, where concave and convex curvatures are treated as Rashba regions with opposite signs. Numerical examples for different separated Rashba-zone geometries calculated within the tight-binding approximation are provided. Remarkably, the spin-polarized current in a system with several Rashba areas can be enhanced with respect to the case with a single Rashba part of the same total area. The enhancement is larger for configurations with multiple regions with the same Rashba sign. This indicates that the increase of the spin polarization is due to the scattering of the electrons traversing regions with and without Rashba interaction. Additionally, we relate the appearance of the spin-polarized currents to novel symmetry relations between the spin-dependent conductances. These symmetries turn out to be a combination of different symmetry operations in real and spin spaces, as those occurring in non-planar systems like carbon nanotubes. Our results show that two-dimensional devices with Rashba spin-orbit interaction can be used as excellent spintronic devices in an all-electrical or mechanical setup. Image 1 [ABSTRACT FROM AUTHOR]

Bilinear magnetoresistance has been studied theoretically in 2D systems with isotropic cubic form of Rashba spin–orbit interaction. We have derived the effective spin–orbital field due to current-induced spin polarization and discussed its contribution to the unidirectional system response. The analyzed model can be applied to the semiconductor quantum wells as well as 2DEG at the surfaces and interfaces of perovskite oxides. • Magnetoresistance (MR) is studied in 2DEG with cubic Rashba spin-orbit interaction. • MR contains a term, that scales linearly with in-plane magnetic field and current. • Bilinear MR results from spin-orbital field due to current-induced spin polarization. [ABSTRACT FROM AUTHOR]

Silicon (Si) is the dominant material in the semiconductor industry with some novel properties, the introduction of germanium (Ge) and vacancies lead to special electronic and magnetic properties. In this work, the effects of spin-polarized electrons regulate the electronic and magnetic properties for substituted Ge in bulk crystalline Si (Ge Si) with vacancies and electrical charge states introduced are investigated based on first-principles calculations. It is found that the electron spin density of Ge-vacancy (GeV) and Ge-divacancy (GeV 2) complex structures is redistributed, the number of the defect energy levels is changed, and the magnetic moment on atoms appears when vacancies are introduced in Ge Si. In addition, the distribution of the defect energy levels in the band gap is affected by charge states (negative and neutral), resulting in changes in the degree of spin-splitting, orbital occupation and electron filling, energy levels degeneracy, and the magnitude of the magnetic moment. These results show that the spin polarization on Ge Si with vacancies and charge states, the number and the distribution of the vacancies around Ge, all play important roles in regulating the magnetic moments, magnetic properties, and the magnitude and distribution of defect energy levels. [ABSTRACT FROM AUTHOR]

Based on Dresselhaus spin-orbit-coupling effect in a layered semiconductor microstructure, an electron-spin filter is proposed. It is found that an obvious spin polarization effect appears and is related to electron energy and in-plane wave vector. It is also found that both magnitude and sign of spin polarization can be controlled by strain engineering or layer's thickness. This layered-semiconductor microstructure can act as a tunable spin filter. • Spin-polarized transport is investigated in InSb/GaSb modulated by Dresselhaus spin-orbit coupling. • An obvious spin polarization appears. • Spin polarization ratio is manipulated by strain engineering or layers' thickness. • A electron-spin filter is obtained for spintronics device applications. [ABSTRACT FROM AUTHOR]

Very recently, two R 3 − c Dirac half-metal materials, LaMnO 3 and MnF 3 , were found and investigated by Du et al. via first principles. They stated that these types of materials with half-metallic band structures and multiple linear band dispersions might exhibit excellent 100% spin polarization and ultrafast electron transport. However, the application of MnF 3 material in the field of spintronics is limited owing to its low Curie temperature (Tc). In this work, we proposed a new half-metal material—MnBO 3. This material satisfies two demands at the same time—it is a half-metal with a high Tc, and it has multiple nearly linear band crossings. The effects of the uniform strain, vacancies, spin–orbit coupling, as well as hole and electron doping on its electronic structures have been discussed in detail. Furthermore, to better study its specific behaviors under extreme conditions, such as high temperature or pressure, we also investigated the thermodynamic properties of MnBO 3 through the quasi-harmonic Debye model. Finally, its thermal stability at room temperature has been proved in this article by means of ab initio molecular dynamics (AIMD) simulations. We hope that MnBO 3 can attract more attention for R 3 − c -type half-metallic materials with linear band crossings and a high Curie temperature in experimental and theoretical areas. • We proposed a R 3 − c robust half-metal with multiple Dirac-like crossings. • The relatively high T c of MnBO 3 makes it more ideal for spintronic applications. • MnBO 3 is thermally stable at room temperature. • The 100% spin polarization comes from its unusual band structures. [ABSTRACT FROM AUTHOR]

We study the spin transport in bilayer graphene nanoribbons (BGNs) in the presence of Rashba spin-orbit interaction (SOI) and external gate voltages. It is found that the spin polarization can be significantly enhanced by the interlayer asymmetry or longitudinal mirror asymmetry produced by external gate voltages. Rashba SOI alone in BGNs can only generate current with spin polarization along the in-plane y direction, but the polarization components can be found along the x, y and z directions when a gate voltage is applied. High spin polarization with flexible orientation is obtained in the proposed device. Our findings shed new light on the generation of highly spin-polarized current in BGNs without external magnetic fields, which could have useful applications in spintronics device design. • Investigate the spin polarized transport properties in bilayer graphene nanoribbons in the presence of Rashba spin-orbit interaction. • Spin polarization can be significantly enhanced by the interlayer asymmetry or longitudinal mirror asymmetry produced by external gate voltages. • Spin current with high spin polarization and high flexibility in the orientation can be obtained in the proposed device. • The proposed device could have useful applications in spintronics. [ABSTRACT FROM AUTHOR]

The property of matter-wave vector solitons in a spin-1 Bose-Einstein condensate with spin-orbit and Zeeman couplings is investigated by multiscale perturbation method. The excitation spectrum and the corresponding state vectors of the system are obtained analytically, and they can be adjusted by the parameters of the system. The bright and dark vector solitons are formulated by reducing the three-component coupled Gross-Pitaeviskii equations to a standard nonlinear Schrödinger equation, which has the solutions of the bright and dark solitons with positive or negative mass depending on the product of the effective dispersive and nonlinear coefficients. The moving vector solitons are demonstrated by adjusting specific momentum near the energy minimum. Finally, the magnetized features of the vector solitons are discussed by the spin polarization of the system. • The excitation spectrum for the vector solitons, determined by the parameters of the system, is obtained analytically. • The analytical bright and dark vector solitons are formulated and the moving solitons are demonstrated by adjusting specific momentum. • The solitons with positive or negative mass depending on the product of the effective dispersive and nonlinear coefficients are analyzed. • The magnetized features affected by spin-orbit and Zeeman couplings are discussed by the spin polarization of the system. [ABSTRACT FROM AUTHOR]

Spin dependent transport in one-dimensional four-terminal rings (FTRs) is investigated in the presence of the Rashba spin-orbit coupling (RSOC). In the absence of the RSOC, the conductances as a function of the electron wave vector show resonant behavior for symmetrical configurations. For asymmetrical configurations, the conductances show peculiar zero-conductance resonances, and two kinds of conductance zeros have been found. In the presence of the RSOC, the original conductance zeros disappear as new conductance zeros are generated. Moreover, two kinds of symmetry relations have been found in the conductances, the spin dependent conductances and the spin polarizations. For the FTRs with axial or central symmetry, the phase-locking effect has been found in terminal 2, where there is no spin polarization. Under a weak magnetic field, the Zeeman term is treated by a perturbation, and it is found that the Zeeman effect is obvious for weak RSOC. • The transmission coefficients for the four-terminal rings (FTRs) are derived analytically. • Two kinds of conductance zeros have been found in the conductances. • The phase-locking effect has been found in terminal 2 for the FTRs with axial or central symmetry. • The results are extended to the case of a weak magnetic perturbation. [ABSTRACT FROM AUTHOR]

• Fully Relativistic PAW band structure of Re(0001) surface. • Identification of surface states and resonances. • Analysis and discussion of the spin-polarization of the surface states. • Comparison with the surface states of Au(111), Pt(111), Ir(111), and Os(0001). We study the electronic structure of the Re(0001) surface by means of ab-initio techniques based on the Fully Relativistic (FR) Density Functional Theory (DFT) and the Projector Augmented-Wave (PAW) method. We identify the main surface states and resonances and study in detail their energy dispersion along the main symmetry lines of the SBZ. Moreover, we discuss the effect of spin-orbit coupling on the energy splittings and the spin-polarization of the main surface states and resonances. Whenever possible, we compare the results with previously studied heavy metals surfaces. We find empty resonances, located below a gap similar to the L-gap of the (111) fcc surfaces, that have a downward dispersion and cross the Fermi level, similarly to the recently studied Os(0001) surface. Their spin polarization at the Fermi level is similar to that predicted by the Rashba model, but the usual level crossing at Γ ¯ is not found with our slab thickness. Moreover, for selected states, we follow the spin polarization along the high symmetry lines, discussing its behavior with respect to k ∥ , the wave-vector parallel to the surface. [ABSTRACT FROM AUTHOR]

Abstract Spin-polarized Goos-Hänchen (GH) displacement is calculated for electrons in a hybrid magnetic-electric-barrier (MEB) nanostructure modulated by spin-orbit couplings (SOCs), which can be realized experimentally by the deposition of a ferromagnetic (FM) stripe and a Schottky-metal (SM) stripe in parallel configuration on the top of the GaAs/Al x Ga 1-x As heterostructure. Both Zeeman interaction (ZI) and SOC are taken into account. It is shown that ZI has less contribution to spin-polarized GH displacement than SOC due to a small g-factor for GaAs. It is also shown that spin-polarized GH displacement can be controlled by Rashba or Dresselhause SOC --interfacial confining electric field or strain engineering, which results hence in a tunable spatial spin splitter for spintronics device applications. Highlights • Spin-dependent Goos-Hänchen effect is investigated theoretically in a hybrid MEB nanostructure modulated by SOCs. • GH displacement and its spin polarization can be tuned by adjusting SOC strength. • Such a device can serve as a controllable spatial spin splitter. [ABSTRACT FROM AUTHOR]

Abstract To investigate the band structure is one of the key approaches to study the fundamental properties of a novel material. We report here the precision band mapping of a 2-dimensional (2D) spin-orbit (SO) coupling in an optical lattice. By applying the microwave spin-injection spectroscopy, the band structure and spin-polarization distribution are achieved simultaneously. The band topology is also addressed with observing the band gap close and re-open at the Dirac points. Furthermore, the lattice depth and the Raman coupling strength are precisely calibrated with relative errors in the order of 10 - 3 . Our approach could also be applied for exploring the exotic topological phases with even higher dimensional system. [ABSTRACT FROM AUTHOR]

In this paper, we study the spin polarization of stationary and moving bright solitons in spin orbit coupled Bose Einstein condensate trapped by a variable shape optical lattice. We particularly investigate the effects of optical lattice parameters, detuning parameter and spin orbit coupling strength on spin polarization. We find that the spin polarization may show different characteristics in different regions of the potential. We also study the dynamical properties of moving bright solitons which change significantly with the optical lattice parameters. The study is performed by using the variational and numerical methods. • Solitons in a variable shape optical lattice potential are investigated. • The parameters effecting the spin polarization are reported. • The dynamical properties of solitons change with the optical lattice parameters. [ABSTRACT FROM AUTHOR]

Featured with the large Rashba constant (α R ∼ 4.2 eVÅ) coupled with the ferroelectricity, GeTe has attracted much interest, proposing novel energy-efficient spintronic devices. However, those approaches are hampered by the high hole density of GeTe around 1020-1021 cm−3, which deteriorates both the ferroelectricity and the bulk Rashba effect of GeTe. To solve this problem, we have investigated the superlattices composed of Bi 2 Te 3 and GeTe ([BT|GT] SL), the former of which is known as a topological insulator (TI) with typically n -type conduction and strong spin-orbit coupling. We have investigated the magnetotransport properties of 25 [BT x |GT y ] z SLs with varying thicknesses (x , y : the thickness in the multiples of the unit cell of the respective layer) of each layer and the repetition number (z) systematically. We have observed a minimum carrier density of 5.7 × 1019 cm−3 in [BT 6 |GeTe 6 ] 6 superlattice sample smaller than that (∼4.4 ×1020 cm−3) of GeTe single film by an order. In addition, we have found that some [BT|GT] SLs with reduced carrier density have a larger Rashba constant compared to that of a single GeTe film. This is explained by the change of the spin polarization which can be modulated by the Fermi level in the Rashba band. These results provide a viable way to realize robust ferroelectricity and strong SOC in GeTe-related material systems simultaneously. • A method to modulate the carrier density in GeTe is proposed, enabling the application of FeRSC to spintronic devices. • The Rashba constant is observed to increase as the carrier density decreases in GeTe/Bi 2 Te 3 superlattice systems. • The reduction of the carrier density in GeTe/Bi 2 Te 3 superlattice systems can be explained in terms of the charge transfer. • Growth techniques of high-quality GeTe/Bi 2 Te 3 superlattices are presented. [ABSTRACT FROM AUTHOR]

• Superconducting NbN has low spin–orbit coupling and makes a good candidate to perform meservey-tedrow measurements. • Using the robust surface oxide, tunnel junctions on NbN can be fabricated using a facile process without lithography. • Due to the high t c of NbN (∼16.5 K), one can perform the spin polarization measurement of ferromagnets at temperatures at high as 1.57 K. We report a two-step process for the fabrication of superconductor-insulator-normal metal tunnel junctions using NbN as the superconducting electrode and its surface oxide as the insulating tunnel barrier, and investigate its efficacy in measuring spin-polarisation of ferromagnets using the Meservey-Tedrow technique. We observe that for NbN film thickness below 10 nm, under the application of parallel magnetic field, the superconducting density of states show clear "Zeeman" splitting into spin-up and spin-down sub-bands. Tunnelling measurements on devices where ferromagnetic Co is used as the normal electrode shows that these devices can be used to measure spin polarisation of a ferromagnet at temperatures up to 1.6 K. The simplicity of our fabrication process makes NbN a very attractive candidate for spin polarisation measurements. Some limitations of this process are also discussed. [ABSTRACT FROM AUTHOR]

Spin transport properties in a non-uniform quantum wire (QW) in the presence of both the Rashba and Dresselhaus spin–orbit couplings (SOCs) is investigated by using the non-equilibrium Green's function (NEGF) method combined with the Landauer Büttiker formalism. It is found that such a non-uniform quantum wire exhibits considerable spin polarization in its conductance in the influence of both the Rashba and Dresselhaus SOCs, and that the two SOCs' strengths strongly affect both the magnitude and sign of the electron spin polarization. Interestingly, the Rashba and Dresselhaus SOCs play the same modulating role in the electron spin polarization. The proposed nanostructure can potentially be utilized to devise an all-electrical spintronic device. [ABSTRACT FROM AUTHOR]

We theoretically studied the effect of interfacial scattering on the transport of charge and spin across the junction of a two-dimensional electron gas with Dresselhaus spin-orbit coupling and ferromagnetic material junction, via the conductance ( G ) and the spin-polarization of the conductance spectra ( P ) using the scattering method. At the interface, not only were the effects of spin-conserving ( Z 0 ) and spin-flip scattering ( Z f ) considered, but also the interfacial Rashba spin-orbit coupling scattering ( Z RSOC ) , which was caused by the asymmetry of the interface, was taken into account, and all of them were modeled by the delta potential. It was found that G was suppressed with increasing Z 0 , as expected. Interestingly, a particular value of Z f can cause G and P to reach a maximum value. In particular, Z RSOC plays a crucial role to reduce G and P in the metallic limit, but its influence on the tunneling limit was quite weak. On the other hand, the effect of Z RSOC was diminished in the tunneling limit of the magnetic junction. [ABSTRACT FROM AUTHOR]

Quantum transport properties and spin polarization in hexagonal graphene nanostructures with zigzag edges and different sizes were investigated in the presence of Rashba spin-orbit interaction (RSOI). The nanostructure was considered as a channel to which two semi-infinite armchair graphene nanoribbons were coupled as input and output leads. Spin transmission and spin polarization in x, y, and z directions were calculated through applying Landauer-Buttiker formalism with tight binding model and the Green's function to the system. In these quantum structures it is shown that changing the size of system, induce and control the spin polarized currents. In short, these graphene systems are typical candidates for electrical spintronic devices as spin filtering. [ABSTRACT FROM AUTHOR]

We give a brief overview about recent developments in theories and experiments on the global and local spin polarization in heavy ion collisions. [ABSTRACT FROM AUTHOR]

By first-principles calculations, we investigated the electronic structures and magnetic properties of several tetravalent transition-metal monolayers with normal honeycomb, triangular-dodecagonal, and square-octagonal structures by considering the effects of spin-orbit coupling and electronic strong correlation of d orbitals. For both standard and corrected approaches, spin-polarized Dirac points contributed by d states appear in the monolayers with hexagonal lattice (honeycomb and 3–12 lattices), but for 4–8 lattices, Dirac points disappear, demonstrating that specific symmetries are required for forming Dirac cones. By adding the on-site Coulomb repulsion, the electronic correlation of d orbital is enhanced and thus the electronic localization increases, aggravating the spin splitting. For Hf3-12, the coexistence of massless Dirac fermions and massive heavy fermions is found. Moreover, the spin-orbit coupling destroys the degeneracy of two bands at K points, and the largest gap opening of 214 meV appears in Hf4-8 due to both Coulomb repulsion and spin-orbit coupling. Our results demonstrate that the spin splitting and gap opening depend on the lattice symmetry, bond length, electronic strong correlation, and spin-orbit coupling. These predicted structures provide new choices in synthesizing two-dimensional transition-metal materials, which has the potential applications in spintronic devices, quantum computation, hydrogen storage, and catalytic chemistry. [ABSTRACT FROM AUTHOR]

It is shown that the Rashba spin–orbit coupling induces the spatially nonuniform spin state in the square-shaped 1D wire. The electron states of this type are characterized with spin orientation changing according to the harmonic motion along the square side. The period of the oscillation is determined only by the spin–orbital coupling and the hopping parameters ratio. The modulation of spin orientation is caused by step-like changing of Rashba field direction. The obtained results were generalized on the case of polygon-shaped wire. [ABSTRACT FROM AUTHOR]

A quadruple quantum-dot (QQD) cell is proposed as a spin filter. The transport properties of the QQD cell were studied in linear response regime on the basis of the equations of motion for retarded Green's functions. The developed approach allowed us to take into account the influence of both intra- and interdot Coulomb interactions on charge carriers' spin polarization. It was shown that the presence of the insulating bands in the conductance due to the Coulomb correlations results in the emergence of spin-polarized windows (SPWs) in magnetic field leading to the high spin polarization. We demonstrated that the SPWs can be effectively manipulated by gate fields and considering the hopping between central dots in both isotropic and anisotropic regimes. [ABSTRACT FROM AUTHOR]

We present here a brief overview of current-induced spin polarization in bulk semiconductors and semiconductor structures of various dimension. The role of band structure and spin relaxation processes is discussed. The related phenomena, such as spin Hall effect, inverse spin Hall effect and other are discussed. Our recent results in this field are presented as well. [ABSTRACT FROM AUTHOR]

The theoretical possibility to use an electron microscope as a spin polarizer is studied. It turns out that a Bessel beam passing a standard magnetic objective lens is intrinsically spin polarized when post-selected on-axis. In the limit of infinitely small detectors, the spin polarisation tends to 100 %. Increasing the detector size, the polarisation decreases rapidly, dropping below 10 −4 for standard settings of medium voltage microscopes. For extremely low voltages, the Figure of Merit increases by two orders of magnitude, approaching that of existing Mott detectors. Our findings may lead to new desings of spin filters, an attractive option in view of its inherent combination with the electron microscope, especially at low voltage. [ABSTRACT FROM AUTHOR]

By using the Green's function formalism, we investigate the effects of single particle energy levels of a quantum dot on the spin-dependent transmission properties through a triple-quantum-dot ring structure. In this structure, one of the quantum dots has been regarded to be non-magnetic and the Rashba spin-orbit interaction is imposed locally on this dot while the two others can be magnetic. The on-site energy of dots, manipulates the interference of the electron spinors that are transmitted to output leads. Our results show that the effects of magnetic dots on spin-dependent transmission properties are the same as the difference of on-site energies of the various dots, which is applicable by a controllable lateral bias voltage externally. Besides, by tuning the parameters such as Rashba spin-orbit interaction, and on-site energy of dots and magnetic flux inside the ring, the structure can be indicated the spin-flip effect and behave as a full spin polarizer or splitter. [ABSTRACT FROM AUTHOR]

Due to the symmetry breaking, Janus two-dimensional materials possess novel electronic properties such as energy valley and spin polarization. In this research, we predicted the Zeeman-type spin splitting and Rashba splitting of monolayer Janus ZrNX (X = Br, I). The Rashba spin splitting and valley splitting can be greatly tuned by the magnetic proximity effect of monolayer H–VTe 2 , which are dependent on the stacking configurations. There is strong interlayer coupling between Janus ZrNX and VTe 2 , leading to a sizable valley splitting of 87 meV. The valley splitting can be significantly enlarged by the vertical compression strain, because of the increases of effective Zeeman field and in-plane orbital component. In addition, a helical gap is opened and the dispersion relation of Rashba spin-orbit coupling is obviously modified by in-plane biaxial strain. The Rashba constant and helical gap increase with the in-plane tensile strain, which leads from the larger potential energy difference and magnetic moment of surface V atoms. The greatly tunable spin/valley splittings in ZrNBr/VTe 2 heterostructure are of some signification for the development of spintronics/valleytronics and the realization of new functional devices. • The valley polarization and Rashba SOC of monolayer Janus ZrNX (X = Br, I) are demonstrated. • The valley splitting and Rashba splitting of ZrNBr/VTe 2 heterostructure are effectively regulated by stacking configurations. • The factor of greater valley splitting is larger in-plane orbital composition and strong effective Zeeman field. • The helical gap is found and can be manipulated by biaxial strain. [ABSTRACT FROM AUTHOR]

In this work we have theoretically studied the band structure and Landau level spectrum of AB Bernal-stacked twisted double bilayer graphene with Rashba spin–orbit interaction. Using the low energy effective theory, we have studied the flat bands bandwidth as a function of twist angle, inter layer coupling strength, interlayer potential difference, and spin–orbit interaction strength. We find that the tunable Rashba spin–orbit interaction strength enhances the flatness of the flatbands. We further predicted an unusual strong spin polarization and multiple crossings of Landau levels with increasing interlayer coupling, Rashba spin–orbit interaction strength, and external bias voltage. • Considered Bernalstacked twisted double bilayer graphene with spinorbit interaction. • Noticed tunable Rashba spinorbit interaction strength enhances flatness of flatbands. • Predicted an unusual strong spin polarization and multiple crossings of Landau levels. • Our results show the tDBG system will be promising material for spintronic devices. [ABSTRACT FROM AUTHOR]

The antiferromagnetic (AFM) CrI 3 bilayer is a particularly interesting representative of van der Waals 2D semiconductors, which are currently being studied for their magnetism and for their potential in spintronics. Using ab initio density-functional theory calculations, we investigate the spin texture in momentum space of the states of the (doubly degenerate) highest valence band of the AFM CrI 3 bilayer with Cr-spin moments perpendicular to the layers. We find the existence, in the main central part of the Brillouin zone, of a Rashba in-plane spin texture of opposite signs on the two layers, resulting from the intrinsic local electric fields acting on each layer. To study the layer segregation of the wavefunctions, we apply a small electric field that splits the degenerate states according to their layer occupancy. We find that the wavefunctions of the highest valence band are layer-segregated, belonging to only one of the two layers with opposite in-plane spin textures, and the segregation occurs over nearly the whole Brillouin zone. The corresponding layer locking of the in-plane-canted spin is related to the separation in energy of the highest AFM band from the rest of the valence bands. We explain how the band interactions destroy the layer locking at the K , K ′ , and Γ points. Furthermore, we compare the layer locking of the in-plane-canted spin in our AFM bilayer system with the hidden spin polarization in centrosymmetric nonmagnetic materials, pointing out the differences in segregation mechanisms and their consequences for the layer locking. We note that a similar Rashba effect with layer locking of in-plane-canted spin could occur in other van der Waals AFM bilayers with strong spin–orbit coupling and an isolated energy band. [Display omitted] • k -space spin-texture is studied for antiferromagnetic chromium-tri-halide bilayer. • Existence of Rashba-type spin textures with opposite spin canting on two monolayers. • Segregation of wavefunctions of highest valence band on one of the two layers. • Layer locking is related to separation in energy of the highest AFM valence band. [ABSTRACT FROM AUTHOR]

The inverse spin Hall effect (ISHE) has been detected and separated from spin rectification effect (SRE) by inverting spin injection direction in metallic system. This work is based on the relation between the two effects and the spin injection direction: the sign of V ISHE changes because of the reversing direction of spin injection while the V SRE is independent on it. According to the different voltage signals before and after the spin injection inverted, the pure V ISHE and V SRE are calculated by utilizing the method of addition and subtraction. The signals can be separated in a wide range of frequency and power. [ABSTRACT FROM AUTHOR]

Diverse electronic structures can be achieved by N-substitution in stable two-dimensional dumbbell carbonitrides. [Display omitted] • A new structure, the DB-C structure, is proposed based on the dumbbell structure predicted in group-IV (Si, Ge, and Pb) monolayer. • Different kinds of DB-C x N y are formed by substituted doping of the C atoms at the bulged site with different amount of N atoms in the DB-C structure. • DB-C 4 N-1 and DB-C 4 N-2 hold the Dirac electronic state with a gap-opening under the influence of spin–orbit coupling. • The DB-C 7 N 3 monolayer is a bipolar magnetic semiconductor. The two-dimensional carbonitrides (C x N y) are attractive materials and their diversified properties play an important role in various fields. In this paper, a dumbbell C x N y is proposed. As graphene is a zero band-gap semiconductor with Dirac cone, while the DB-C monolayer formed by adding C atoms to graphene is an indirect-gap semiconductor with a band-gap of 1.69 eV. The various DB-C x N y are formed by substituted doping of the C atoms at the bulged site with different amount of N atoms. There are four bulged C in a unit cell of DB-C. DB-C 9 N has a metallic behavior, evolved by n-type doping. DB-C 4 N-1 and DB-C 4 N-2 hold the Dirac electronic state with a gap-opening under the influence of spin–orbit coupling, while DB-C 4 N-3 is an indirect-gap semiconductor. Of all DB-C x N y , only DB-C 7 N 2 and DB-C 7 N 3 are magnetic, but DB-C 7 N 2 has a metallic behavior and DB-C 7 N 3 is a bipolar magnetic semiconductor with controllable spin polarization. DB-C 6 N 4 is a nonmagnetic semiconductor with a direct band-gap of 0.80 eV. The stability of all DB-C x N y monolayers is verified by the phonon spectrum. Due to the unique geometric structure, tunable electronic properties, and high specific surface area, DB-C x N y monolayers may be well applied in photocatalysis, electrocatalysis, spintronic and energy storage devices. [ABSTRACT FROM AUTHOR]

Resorting to an external gate potential, we explore the spin–orbit coupling (SOC) in n-quantum-well structures with n subbands occupied, since n-well configuration is favorable to the flexible control of n-subband occupation for electrons in experiments. The charge transfer among the multiple local wells provides more possibilities of manipulation of the Rashba SOC. For all the systems we construct, from triple- to septuple-quantum-well structures, the SOC coefficient of the lowest subband is always much larger than those of the other subbands, which leads to greater spin splitting, conducive to desirable spin polarization. Furthermore, we demonstrate selective control of SOC via adjusting the gate, i.e., separately tuning the SOC coefficients of certain subbands while leaving those of the others unaffected by the gate. However, when more local wells are incorporated, the SOC coefficients of all subbands become weak gate-dependent in the case of n-subband occupation. All these findings are attributed to the charge redistribution among the subwells and the variation gradient of the potential energy along the growth direction of the quantum wells. Our results should provide new insight for experimental manipulation of the Rashba SOC in multiple-well structures. • Selective control of Rashba SOC of different subbands is realized in a wide gate potential range , facilitating the realization of persistent spin helix in quantum well semiconductors, which is crucial for spin-coherent transport. • Large spin splitting of the lowest subband is demonstrated, constructive to desirable spin polarization and detection. • When more local wells are incorporated, in the gate range where n subbands are kept occupied , Rashba SOC of all subbands become less gate-dependent. [ABSTRACT FROM AUTHOR]

We discuss the localization and spin dynamics of tunable spin-orbit coupled Bose-Einstein condensates in deep optical lattices. Rich localized phenomena (breather, soliton, self-trapping, and diffusion) are observed. The critical conditions for occurring different localized states are obtained analytically and confirmed numerically. Under the critical conditions, we observe localized states with fixed initial spin polarization. When the critical condition is not satisfied, because of spin-momentum locking, quenching of Raman coupling from soliton state excites spin dynamics. If initially the soliton is in a nearly unpolarized (polarized) state, persistent (damped) spin dynamics is excited. The system finally transforms to a new polarized state in the damped spin dynamics. The localization and spin dynamics can be well controlled by periodic modulation of Raman coupling. • Localization and spin dynamics of tunable SOC BECs in deep optical lattices are studied. • Rich localized states (breather, soliton, and self-trapping) with fixed spin polarization are predicted. • The critical conditions distinguish different localized states are obtained analytically. • Persistent (damped) spin dynamics is excited by quenching Raman coupling from soliton state. • We provide a way for manipulating the localization and spin dynamics in SOC BECs. [ABSTRACT FROM AUTHOR]

We report a theoretical study of the spin and valley dependent transport properties in a WSe 2 superlattice with external Rashba spin-orbit interaction (ERSOI). It is shown that the conductance with and without spin flip strongly depends on the ERSOI and has an oscillatory behavior with respect to ERSOI strength, thus WSe 2 superlattice can act as a spin-converter. Also, the magnitude of spin-dependent conductance can be efficiently controlled by potential barrier height and number of superlattice barriers. Results show that the valley and spin polarization depend on the number of superlattice barriers and exhibit an oscillatory evolution versus ERSOI strength and potential barrier height. These results clarify that a WSe 2 superlattice can be useful for the design of novel valleytronic and spintronic devices. [ABSTRACT FROM AUTHOR]

Spin-polarized He + ion scattering spectroscopy (SP-ISS) study on a polycrystalline Sn target surface is reported. We observed substantial spin dependent He + ion scattering on the non-magnetic Sn target. It is not due to He + ion neutralization, but it is attributed to spin–orbit coupling (SOC) that acts transiently on the He + 1 s electron spin in the He + –Sn atom binary collision. We found that the spin dependent scattering quantified as the spin asymmetry exhibits periodic oscillation with the reciprocal of the He + ion velocity. The oscillation originates from the SOC induced-slight energy difference of the [He + –Sn] and [He 0 –Sn + ] systems which are involved in the quasi-resonant charge transfer. The oscillatory spin asymmetry shows that SOC arises from collision induced intermediate state. [ABSTRACT FROM AUTHOR]

We study the possibility to control the spin polarization and spin-dependent transport in a graphene sheet by considering a ferromagnetic layer in the presence of the Rashba spin–orbit interaction. Studying the scattering problem with the help of the Green function (which was found explicitly), we obtained simple analytical expressions for the spin dependent transmission probability. Using the small exchange parameter and Rashba coupling constant, we can obtain any degree of spin polarization, but in the case of a small interaction region, only for slow electrons. [ABSTRACT FROM AUTHOR]

The strain effects on the edge-state transport of the zigzag monolayer for a molybdenum disulfide nanoribbon are investigated numerically using a six-band tight-binding model with KWANT, where the strain effect was absorbed into the modified hopping coefficients. For metallic edge-states in a zigzag nanoribbon, introducing both an intrinsic spin–orbit coupling and local exchange field effects breaks the spin degeneracy and spin inversion symmetry to enable spin selective transport. Changes in the energy dispersion of the metallic edge-states due to uniaxial strain are asymmetric with respect to the strain direction. Transitions from metallic to insulating edge modes occur for a tensile strain of approximately 5% along the x -direction, but no such transition has been observed up to a tensile strain of 10% along the y -direction. The edge-current transmission and spin-polarized edge-currents are determined primarily by details of the energy dispersion of edge-states and are strongly affected by the incident energy of carriers for a given strain. The fully spin-polarized edge-currents can be obtained by modulating both the Fermi energy and gate potential. The results provide useful information to implement a spin-polarized current as a potential solution for wearable spin devices. [Display omitted] • The strain effects on the edge-state transport for a molybdenum disulfide nanoribbon. • Asymmetric change of the energy dispersion of the edge states with respect to the strain direction. • Transitions from metallic to insulating edge modes due to tensile strains. • The spin-polarized edge currents in a three terminal field effect transistor. [ABSTRACT FROM AUTHOR]

The properties of PuN (0 0 1) surface have been investigated using all-electron full-potential linearized augmented plane wave plus local orbitals basis (FP-LAPW+lo) method at both scalar- and fully- relativistic levels, with and without spin-polarization. The ground state of PuN (0 0 1) surface is found to be ferromagnetic with spin–orbit coupling (FM + SO). At the ground state, the semi-infinite surface energy and average work function for PuN (0 0 1) surface are predicted to be 1.12 J/m 2 and 2.62 eV, respectively. At three layers of formula units and beyond, the PuN (0 0 1) surface properties including total energies per N -formula unit, surface energy, work function and magnetic moment converge, indicating that a 3-layer slab can be used to model PuN (0 0 1) surface to a good approximation. The localization of the 5 f electron states is pronounced at the top surface layer while bulk-like behavior is exhibited at the second and deeper layers. [ABSTRACT FROM AUTHOR]

We present a first-principle investigation of the fully relativistic electronic surface states and resonances of clean Pt(111) and Ir(111) and compare them with those of Au(111). Our calculations are based on a recently introduced fully relativistic projector augmented-wave (PAW) approach that includes spin-orbit coupling and allows us to access both the relativistic energy splittings and the spin polarization of the surface states. The maps of the electronic structure of the two surfaces are critically discussed in comparison with previous calculations and with some of the available angle-resolved photoelectron spectroscopy data. [ABSTRACT FROM AUTHOR]

The geometric symmetry of the surface plays an important role for the spin–orbit-induced spin texture of two-dimensional electronic states. This article reviews the peculiar Rashba spins induced by a C 3 symmetry, including the completely spin polarized surface states with the polarization vector oriented perpendicular to the surface, i.e. a direction that is not expected in a typical Rashba system. This review also describes that this peculiar Rashba situation has possibility to suppress backscattering and therefore to greatly improve the efficiency of spin transport, which is an essential issue in the development of high-performance semiconductor spintronic devices. [ABSTRACT FROM AUTHOR]

The surface of W(1 1 0) exhibits a flattened Dirac-cone-like surface state S 1 with a remarkable spin texture within a spin–orbit-induced symmetry gap. Along Γ S ¯ , S 1 hybridizes spin-selectively with an almost spin-degenerate surface state S 2 . Beyond the spin-selective hybridization point, the surface state S 2 exhibits a spin splitting with a change of the spin polarization at the band bottom. For normal electron emission, S 1 shows spin-dependent intensities depending on the experimental geometry. This behavior is understood as a consequence of a mixed Σ 1 and Σ 3 symmetry of the state. This finding opens a new pathway to studies of the orbital symmetry of electronic states in solids with spin–orbit interaction, without the need of polarization-dependent ARPES. [ABSTRACT FROM AUTHOR]

The robust effect of curvature on spin polarization is reported in a three-terminal bridge system where the bridging material is subjected to Rashba spin–orbit interaction. The results are examined considering two different geometric configurations, ring- and linear-like, of the material which is coupled to one input and two output leads. Our results exhibit absolute zero spin polarization for the linear sample, while finite polarization is obtained in output leads for the ring-like sample. [ABSTRACT FROM AUTHOR]

We theoretically investigate the electron transport properties in a non-magnetic nanostructure with spin–orbit interactions and the δ -doping which can be experimentally realized by using metal-organic chemical-vapor deposition or molecular beam epitaxy. We find that the electron transmission and the spin polarization strongly depend not only on the height and the width of the barrier but also on the weight and the position of the δ -doping. These interesting phenomena may be very helpful for understanding the electron transport mechanism in a non-magnetic nanostructure and designing the δ -doping-tunable spintronic device based on the non-magnetic heterostructure. [ABSTRACT FROM AUTHOR]

We present a theoretically investigation about the electron transport through a single-barrier structures in HgTe/CdTe quantum wells (QWs) with inverted band structure. For HgTe/CdTe QWs structure, the transmission probabilities show great dependence on the Rashba spin–orbit interaction (RSOI), the incident angle, the incident Fermi energy and the electric modulation potential. By tuning the modulation amplitude with gate voltage or the strength of RSOI modulation, the efficient spin-polarized P Z = 1 is achieved, which is formed due to the spin-split in band spectrum induced by the RSOI modulation. This electric mechanism provides us a way to manipulate the spin polarization electrically and convenient for experimental verification. [ABSTRACT FROM AUTHOR]

We study the quantum capacitance and the Landau levels (LLs) in n-type monolayer InSe subjected to a vertical magnetic field. Starting from a single band k ⋅ p Hamiltonian, we analytically obtain the LLs by solving the Hamiltonian and find that the LLs have a uniform distribution on the LL index and magnetic field, i.e., the equal LL spacings. Further, the LLs are fully spin polarized under moderate magnetic fields originating from the spin–orbit coupling and Zeeman splitting. The magneto-capacitance peaks show one-to-one correspondence to the LLs, resulting in a perfect square-wave-shaped spin polarization. Our results is useful to detect the effective mass and spin–orbit coupling parameters of n-type monolayer InSe and design spintronics devices based on it. • We analytically obtain the Landau levels and magneto-capacitance of n-type monolayer InSe. • The Landau levels are spin-polarized due to the spin orbit coupling and Zeeman splitting, resulting fully spin-polarized magneto-capacitance. • The magneto-capacitance spectrum is useful to determine the band parameters and design spintronic devices. [ABSTRACT FROM AUTHOR]

We present a theoretically investigation about the electron transport through a single-barrier structures in HgTe/CdTe quantum wells (QWs) with inverted band structure. For HgTe/CdTe QWs structure, the transmission probabilities show great dependence on the Rashba spin–orbit interaction (RSOI), the incident angle, the incident Fermi energy and the electric modulation potential. By tuning the modulation amplitude with gate voltage or the strength of RSOI modulation, the efficient spin-polarized P Z = 1 is achieved, which is formed due to the spin-split in band spectrum induced by the RSOI modulation. This electric mechanism provides us a way to manipulate the spin polarization electrically and convenient for experimental verification. [ABSTRACT FROM AUTHOR]

We design an A-B interferometer with a "single quantum dot atom" embedded in the upper arm and a "double quantum dot molecule" embedded in the lower arm. The transmission coefficient and average current characteristics are studied as the time-dependent external field is introduced. When the interdot coupling strength is weak, the change of Rashba spin orbit coupling strength has a strong influence on the spin transmission coefficient. When the interdot coupling strength and Rashba spin orbit coupling strength take appropriate values, the spin up and spin down transmission coefficients completely coincide, and a resonance band emerges at the Fermi level. The spin polarization can be close to +1 or −1 by adjusting the Zeeman magnetic field, the interdot coupling strength, and the gate voltage. In the presence of photon assistance, the spin polarization changes periodically in a certain proportion, so as to realize the spin-polarized transport with controllable time-dependent external field. These findings provide a theoretical basis for the spin polarized function of A-B interferometer. • The spin transmission coefficient produces Fano effect at the Fermi level. • The system can be used as a spin filter by adjusting the Zeeman magnetic field and the gate voltage. • When the time-dependent external field is introduced, the spin polarization changes quasi periodically. • The system can be used to realize the electrical components of spin current polarization transport unit. [ABSTRACT FROM AUTHOR]