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The second-order nonlinear Hall effect in 8-Pmmn monolayer borophene under the influence of an out-of-plane electric field and intrinsic spin–orbit interaction is reported. This unconventional response sensitive to the breaking of discrete and crystal symmetries can be tuned by the applied electric field, which can vary the bandgap induced by spin–orbit coupling. It is described by a Hall conductivity tensor that depends quadratically on the applied electric field. We find that the nonlinear Hall effect strongly depends on the spin polarization. In particular, it exhibits out of the phase character for spin-up and spin-down states. Remarkably, it undergoes a phase flip in the spin-up state at a large out-of-plane electric field that generates a staggered sublattice potential greater than the spin–orbit interaction strength. It is shown that the nonlinear Hall effect in the system originates from the broken inversion symmetry that plays an indispensable role in developing finite Berry curvature and its relevant dipole moment. It is found that at zero temperature, the nonlinear Hall response is maximal when the Fermi energy is twice the bandgap parameter and vanishes at large Fermi energies. Notably, the peak of nonlinear Hall response shifts to lower Fermi energies at finite temperature. [ABSTRACT FROM AUTHOR]

Using low and optimized magnetic field along with electric field is a novel strategy to facilitate electrochemical nitrite reduction reaction (NO2RR). Herein, the magnetic field assisted electrocatalytic ammonia synthesis employing spin‐thrusted β‐MnPc at 95 mT magnetic field is explored. The calculated rate of ammonia generation is 16603.4 µg h−1 mgcat−1, which is almost twice that of the nonpolarized manganese phthalocyanine (MnPc) catalyst. Additionally, the Faradaic efficiency (FE) at –0.9 V versus RHE is found to be 92.9%, significantly higher compared to the nonpolarized MnPc catalyst. In presence of external magnetic field, MnPc catalysts provide a better electron transfer channel which results in a lower charge transfer resistance and hence better electrochemical performances. Density functional theory (DFT) result further verifies that magnetic field induced β‐MnPc has a lower potential barrier (0.51 eV) for the protonation of NO* than nonpolarized β‐MnPc (1.08 eV), which confirms the enhanced electrochemical nitrite reduction to ammonia. [ABSTRACT FROM AUTHOR]

The Rashba spin–orbit coupling (RSOC) effect on the polarization and shot noise properties in a strained WSe2 multiple barrier structure is studied by transfer-matrix technique. The results indicate that the spin-dependent Fano factor depends on the strain and RSOC strength with oscillatory evolution. Thus, the value of Fano factor with spin rotation can be tuned mechanically and by an external electric field. Also, Fano factor shows high sensitivity to the number of electrostatic barriers in strained WSe2 multiple barrier structure. Meanwhile, in a strained WSe2 multiple barrier structure both sign and value of the valley and spin polarizations could be adjusted by tuning both RSOC and strain strength. These findings show that a WSe2 multiple barrier structure under strain and RSOC can be useful for future spintronics, straintronic and valleytronic devices. [ABSTRACT FROM AUTHOR]

Valleytronics has attracted much attention due to its potential applications in information progress and data storage. In this paper, monolayer Cr2S3 is proven to be a ferromagnetic (FM) semiconductor by using first-principles calculations. Moreover, monolayer Cr2S3 exhibits a perpendicular magnetic anisotropy energy of 30 μeV/f.u. Surprisingly, monolayer Cr2S3 presents spontaneous valley polarization, which means that it will be nonvolatile for data storage. Notably, monolayer Cr2S3 changes to an antiferromagnetic (AFM) state from the original FM state under biaxial tensile strain, and its easy axis will be reorientated from out-of-plane to in-plane when the compressive strain is larger than −2%. Importantly, for AFM monolayer Cr2S3, the valley polarization reversion can be realized by an external electric field along the z direction. In brief, valley polarization has been achieved in both FM and AFM monolayer Cr2S3, which is very rare in other valleytronics research. The present research provides a tantalizing candidate for realizing and manipulating valley and spin physics. [ABSTRACT FROM AUTHOR]

Combining chirality with ferromagnetism is challenging in organic materials and may bring potential application for the cross-integration of multiple disciplines. In this work, we achieved the intrinsic coexistence of chirality and spontaneous spin polarization in the diblock copolymers, where left-handed and right-handed circularly polarized lights present tunability on both the circular dichroism and spin polarization. Without electron dependence of transport in chiral copolymer, chirality is still coupled with spin. The phenomenon observed here is not the traditional chirality induced spin selectivity effect. Moreover, the electric field could also effectively tune the chirality dependence of circular dichroism to further affect the magnitude of spin polarization. Thus, a strong relationship between the chirality and spin polarization is formed in chiral copolymers. In addition, because of the different molecular packing for chiral enantiomers, electron–phonon coupling strengths are different to lead to a difference in spin polarization. Overall, the properties of chirality, spontaneous spin polarization, and photon-chirality-spin coupling are developed and studied, which effectively promotes the ability of potential applications of chiral copolymers. [ABSTRACT FROM AUTHOR]

[Display omitted] The efficiency of CO 2 photocatalytic reduction is severely limited by inefficient separation and sluggish transfer. In this study, spin polarization was induced and built-in electric field was strengthened via Co doping in the BiVO 4 cell to boost photocatalytic CO 2 reduction. Results showed that owing to the generation of spin-polarized electrons upon Co doping, carrier separation and photocurrent production of the Co-doped BiVO 4 were enhanced. CO production during CO 2 photocatalytic reduction from the Co-BiVO 4 was 61.6 times of the BiVO 4. Notably, application of an external magnetic field (100 mT) further boosted photocatalytic CO 2 reduction from the Co-BiVO 4 , with 68.25 folds improvement of CO production compared to pristine BiVO 4. The existence of a built-in electric field (IEF) was demonstrated through density functional theory (DFT) simulations and kelvin probe force microscopy (KPFM). Mechanism insights could be elucidated as follows: doping of magnetic Co into the BiVO 4 resulted in increased the number of spin-polarized photo-excited carriers, and application of a magnetic field led to an augmentation of intrinsic electric field due to a dipole shift, thereby extending carrier lifetime and suppressing charges recombination. Additionally, HCOO− was a crucial intermediate in the process of CO 2 RR, and possible pathways for CO 2 reduction were proposed. This study highlights the significance of built-in electric fields and the important role of spin polarization for promotion of photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]

Based on the recursive Green-function method together with Landauer–Büttiker formalism, the spin-dependent transport properties of electrons in a zigzag silicene nanoribbon embedding multiple rectangular quantum dots (QDs) are investigated. According to an analysis of the energy band under the periodically distributed electric field and exchange ferromagnetic field, the parallel exchange field induced by the ferromagnetic insulators eliminates the spin degeneracy, which leads to spin-polarized transport in the proposed structure. By tuning a periodic electric field, we found the relationship between the number of QDs and the splitting peak for conductance in the anti-parallel exchange field. We discover the population of electrons near QDs by calculating the local density of states. The effect of the geometry of periodic QDs on the shift of resonance peak is evaluated. The spin polarization is further explored for various configurations of electric field and exchange field in order to manipulate the spin filtering more effectively. The results provide an avenue to design a controllable spin bandpass filter with the modulation of electric field and exchange field. [ABSTRACT FROM AUTHOR]

Equiprobable incoherent mixtures of two totally polarized states of light whose associated three-dimensional Jones vectors are mutually orthogonal are called discriminating states and constitute a peculiar type of state that plays a key role in the characteristic decomposition of a generic state into a totally polarized state, a totally unpolarized state, and a discriminating state. In general, discriminating states are three-dimensional, in the sense that the strengths of the three components of the electric field are nonzero for any Cartesian reference frame considered. In the limiting case that the electric field evolves in a fixed plane, the discriminating state is said to be regular and corresponds to a two-dimensional unpolarized state. The special features of discriminating states cover, e.g., their possible synthesis from infinite pairs of mutually orthogonal states as well as their transverse spin. The nature and properties of discriminating states are comprehensively analyzed based on their associated intrinsic Stokes parameters, which leads to meaningful interpretations in terms of the associated polarization ellipsoids and spin vectors. [ABSTRACT FROM AUTHOR]

Herein, the spin‐polarized edge‐state transport properties in L‐shaped zigzag MoS2$\left(\text{MoS}\right)_{2}$ nanodevice (L-zMoS2ND$\left(\text{L�?zMoS}\right)_{2} \text{ND}$) are investigated based on tight‐binding model, Green's function method, and ballistic transport theory. The spin conductance and spin polarization are calculated by considering external exchange field and electric field. It is shown in the results that the spin conductance is closely related to the configuration of atomic non‐consistence on the edge of L-zMoS2ND$\left(\text{L�?zMoS}\right)_{2} \text{ND}$. Meanwhile, the spin conductance is determined by the spin channel opening on the edge, which can be modulated by external fields. The configuration characteristic and external fields give rise to effects of sublattice mismatch and spin mismatch on the edge channels, respectively. As a consequence, mismatch effects are actually employed to modulate the spin channel on the edge of L-zMoS2ND$\left(\text{L�?zMoS}\right)_{2} \text{ND}$, and 100% spin polarization is realized selectively. Moreover, the corresponding local density of states distributions are plotted to reveal the modulation of the spin‐resolved edge‐state and the spin‐filtering effects in the real space. These spin‐polarized edge‐state transport properties in L-zMoS2ND$\left(\text{L�?zMoS}\right)_{2} \text{ND}$ can have potential application in various kinds of spin valves and spin filters in nanocircuits. [ABSTRACT FROM AUTHOR]

The antichiral edge states induced by the modified Haldane model have been predicted in the previous studies. In this study, other types of antichiral edge states are proposed by applying the side potentials composed of a potential field, staggered electric field, and exchange field along the boundaries of zigzag honeycomb nanoribbons (zHNRs). Their corresponding transport properties are investigated. The results show that the side potentials can lift the spin degeneracy of the edge modes, inducing five types of antichiral edge states. By calculating the spin-dependent energies in K' and K valleys of the edge modes, an interpretation for generating antichiral edge states is proposed. In addition, the spin/charge switcher in the three-terminal device consisting of zHNRs is developed based on the induced edge states. We believe that these results can be used in the design of future spintronic devices. In the modified Haldane model, antichiral edge states appear at the boundary of zigzag honeycomb nanoribbons. These flow oppositely at the boundary and the center of the ribbon. In this work, the authors show how to decorate the system boundary to control the edge modes' current and spin polarization. They show how to form a three-terminal system where an unpolarized current splits into two fully spin-polarized ones. [ABSTRACT FROM AUTHOR]

The spin-photo current in single layer stanene and germanene under a linearly polarized light is theoretically investigated based on the tight-binding Hamiltonian combined with the nonequilibrium Green's function at room temperature. The results show that by considering the simultaneous effect of the linear illumination and a vertical external electric field without any magnetic exchange element, pure spin-photo current without charge current is generated in two-dimensional lattices with a large intrinsic spin–orbit coupling. The necessity of enhanced spin life-time for detection of spin polarization can be explained by spin-valley locking concept. Spin-valley locking arises in buckled two-dimensional materials as a result of the large spin–orbit coupling and electric-field reversible valley spin polarization. Equal absorption of the linearly illumination at both valleys with different spin polarization, leads to pure spin-photo current injection. In addition, an acceptable photoresponsivity has been reported in a broad range of photon energy. The numerical results indicate high quantum efficiency with a maximum of nearly 83% and 50% for stanene and germanene, respectively. This work may pave theoretical reference toward design of new spin-optoelectronic devices based on satanene and germanene junctions with high performance. [ABSTRACT FROM AUTHOR]

For the application of the spintronics devices, large Rashba spin splitting and Zeeman spin splitting are required. However, the absence of spin splitting in the non-polar MXene Lu 2 CT 2 (T = F, OH) with mirror symmetry limits the functionality of the spintronics applications. In this paper, by the density functional theory calculation, the effect of the electric field on the electronic properties along with the spin polarization of MXene Lu 2 CT 2 (T = F, OH) are investigated. For Lu 2 CF 2 , the electric field can effectively regulate the energy band structures resulting in the indirect-direct band gap transition and semiconductor-metal transition. The spin splitting and spin polarization that are not observed in the situation of the intrinsic systems are established due to the breaking of the mirror symmetry by a suitable external electric field, which is sufficient to support the spintronics functionality. Furthermore, the electric field can effectively control the in-plane Rashba spin splitting and out-of-plane Zeeman spin splitting. The parameters of Rashba and the warping coefficients are comprehensively studied by using the effective k · p model. Therefore, our results provide a possible way to induce and tune Rashba spin splitting and Zeeman spin splitting in the MXene by an external electric field, which is useful for spintronic devices. [Display omitted] • We offer a possible way to induce and tune Rashba effect in no-polar MXene by an external electric field for spintronic devices. • The parameters of Rashba and the warping coefficients are comprehensively studied by using the effective k · p model. • We offer a possible way to induce and tune Rashba effect in no-polar MXene by an external electric field for spintronic devices. [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]

Based on a double-layered semiconductor nanostructure (DLSN)-InSb/GaSb, we propose a controllable electron-spin filter for spintronics device applications. Electron-spin polarization is induced by Rashba spin-orbit coupling inside the DLSN. Both magnitude and sign of spin polarization ratio can be manipulated by externally-applied electric field or the semiconductor-layer thickness. [ABSTRACT FROM AUTHOR]

In this article, for the first time, we propose a silicene-based spin filter having a TFET configuration. The device portrays a voltage-dependent spin polarization and achieves a “spin polarization” as high as 98% at a minimal “operating voltage” (0.35 V). The operation of the device is based on the “spin-polarized edge states” in a silicene nanoribbon. The “spin polarization” of the output current can be tuned by modifying the bandgap of the spin-up and spin-down states via an in-plane perpendicular “electric field” generated by two “lateral gates.” The device features high spin polarization apart from its expected integration with Si-based technology. The proposed device has a simple construction, wherein a single layer of Si atoms achieves such a high value of spin polarization at a minimal operating voltage. The operation of the proposed device is demonstrated by using the first-principles quantum transport simulations. [ABSTRACT FROM AUTHOR]

Magnetic field dependence of the electronic spin polarization (P), polarization decay and spin oscillation in gallium arsenide quantum wells is investigated by spin-resolved photoluminescence measurements. In the presence of a magnetic field in the Voigt configuration, the spin-polarized electrons, generated by a circularly polarized light, are drifted by an electric field. The results show that P decays and oscillates with time as well as with the magnetic field. However, the electric field is found to play a vital role in spin dynamics and exchange coupling between the electron and hole spins in the wells. [ABSTRACT FROM AUTHOR]

Electrical control on interfaces is one of the key approaches to harvest advanced functionalities in modern electronic devices. In this work, it is proposed and demonstrated that a "battery‐like" tunnel junction structure can be embedded with added control and functionalities via reversible lithium‐ion motion. In a model system of FeCo/FeCoOx/LiF/FeCo magnetic tunnel junctions, the ultrathin LiF barrier makes strong electric fields possible under moderate applied voltages, and can therefore electrically drive reversible lithium‐ion migration within the barrier. The ion motion subsequently leads to reversible interfacial modifications that generates over a thousand percent resistance change across the devices. Meanwhile, sizable tunneling magnetoresistance persists and even reverses the sign of spin polarization as a function of the interfacial control. The devices are therefore responsive to both electric and magnetic field manipulations, giving rise to diverse and nonvolatile functionalities. [ABSTRACT FROM AUTHOR]

Electric field control of magnetic properties has been achieved across a number of different material systems. In diluted magnetic semiconductors (DMSs), ferromagnetic metals, multiferroics, etc., electrical manipulation of magnetism has been observed. Here, we study the effect of an electric field on the carrier spin polarization in DMSs (GaAsMn); in particular, emphasis is given to spin-dependent transport phenomena. In our system, the interaction between the carriers and the localized spins in the presence of electric field is taken as the main interaction. Our results show that the electric field plays a major role on the spin polarization of carriers in the system. This is important for spintronics application. [ABSTRACT FROM AUTHOR]

While the spin of two-dimensional polarization states admits a simple representation, its physical interpretation for three-dimensional (3D) mixed polarization states requires a more involved analysis. In this work, we address the spin structure of the electric field of a general 3D polarization state by taking advantage of the characteristic decomposition and the recently introduced notion of nonregularity associated with 3D states. We show that a nonregular polarization state necessarily has an additional spin component due to the state's genuinely 3D nature, and both the orientation and magnitude of the spin are regulated by the degree of nonregularity. The results provide new physical insight into partially polarized evanescent and tightly focused light fields in which strong nonregular character has recently been demonstrated. [ABSTRACT FROM AUTHOR]

In this work, we address the fundamental question of whether a magnetic material having zero net magnetization can produce polarized spin current from a completely unpolarized one. Common wisdom suggests that this is not possible, but if we break the symmetry in hopping integrals in different segments of the magnetic sample, then a finite possibility of getting polarized spin current is established. To substantiate this fact, we consider a one-dimensional magnetic chain with vanishing net magnetization where one part of the chain is subjected to an ac electric field, keeping the other part free. The ac field, introduced through Peierls substitution, modulates the hopping integrals yielding a misalignment of up and down spin channels, which is the primary requirement to get finite spin polarization. Simulating the system within a tight-binding framework, we compute spin-dependent transmission probabilities using the well-known Green's function prescriptionand determine junction currents following the Landauer–Büttiker formalism. Our analysis may shed some light on designing spin-polarized devices using driven magnetic materials with vanishing net magnetization. [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]

The spin-dependent electron transport properties of zinc- and manganese-doped adenine molecules connected to zigzag graphene leads are studied in the zero bias regime using the non-equilibrium Green's function method. The conductance of the adenine molecule increased and became spin-dependent when a zinc or manganese atom was doped into the molecules. The effects of a transverse electric field on the spin-polarization of the transmitted electrons were investigated and the spin-polarization was controlled by changing the transverse electric field. Under the presence of a transverse electric field, both the zinc- and manganese-doped adenine molecules acted as spin-filters. The maximum spin-polarization of the manganese-doped adenine molecule was greater than the molecule doped with zinc. [ABSTRACT FROM AUTHOR]

III‐nitride wide bandgap semiconductors are favorable materials for developing room temperature spintronic devices. The effective manipulation of spin dynamics is a critical request to realize spin field‐effect transistor (FET). In this work, the dependence of the spin relaxation time on external strain‐induced polarization electric field is investigated in InGaN/GaN multiple quantum wells (MQWs) by time‐resolved Kerr rotation spectroscopy. Owing to the almost canceled two different spin–orbit coupling (SOC), the spin relaxation time as long as 311 ps in the MQWs is obtained at room temperature, being much longer than that in bulk GaN. Furthermore, upon applying an external uniaxial strain, the spin relaxation time decreases sensitively, which originates from the breaking of the SU(2) symmetry. The extracted ratio of the SOC coefficients shows a linear dependence on the external strain, confirming the essential role of the polarization electric field. This effective manipulation of the spin relaxation time sheds light on GaN‐based nonballistic spin FET working at room temperature. [ABSTRACT FROM AUTHOR]

We have studied the spin relaxation dynamics in both n- and p-type layered bulk WSe2 under a perpendicular electric field by employing time-resolved Kerr rotation and helicity-resolved transient reflection measurements. The experimental results reveal the efficient tuning of spin relaxation time from 3 ps to 46 ps by the external electric field at 10 K. The dependence of spin relaxation time on the external electric field is understood based on active interlayer hopping. These studies demonstrate the gate-tunable spin polarization and relaxation in bulk transition metal dichalcogenides (TMDCs), which are fundamentally important for understanding spin dynamics and the practical design of spintronic devices based on bulk TMDCs. [ABSTRACT FROM AUTHOR]

• The intrinsic magnetic properties can be modulated by geometrical configuration. • The spin degeneracy semiconducting ground state can be lifted by electric field. • The half-metallicity can be induced at critical electric field strength. It has been known for a long time that graphene flakes of certain geometries can develop spontaneous spin polarization. Here, it is studied what happens when two triangular graphene nanoflakes, possibly different sizes, are placed in close proximity with AB (Bernal) stacking. The results of first-principles calculations show that the magnetic ground state of the bilayer system depends on the different sizes of the two nanoflakes, and spin-related energy gap can be controlled with external electric fields. Under certain circumstances, the system even can be tuned into half-metallic nature, which might potentially be exploited in future spintronics applications. [ABSTRACT FROM AUTHOR]

This review article summarizes recent developments related to the dynamical formation of persistent spin helices in GaAs- and CdTe-based heterostructures. We start with fundamental aspects of spin-orbit interaction in quantum wells, in particular the Dresselhaus and Rashba terms and their relation to the bulk and structural inversion asymmetries, respectively. In the regime of balanced interactions, their combined impact gives rise to the formation of the persistent spin helix, i.e., a regime where a unidirectional spin grating with enhanced coherence time is established. The experimental scheme relies on ultrafast Kerr microscopy and permits to excite the spin polarization and detect it with a simultaneous spatial and temporal resolution of micrometers and picoseconds, respectively. For a microscopic understanding and a description of the results, kinetic theory of spatio-temporal spin dynamics of two-dimensional electrons is presented. In addition, Monte Carlo simulations of the spin distribution function are performed. Based on these concepts we discuss three areas with recent advances in the field of spin helices. (i) Anisotropic spin transport and spin helix dynamics in a modulation-doped GaAs quantum well is analyzed. It is observed that application of an out-of-plane electric field changes spin-orbit interaction through the Rashba component and the cubic Dresselhaus term. Remarkably, a weak in-plane electric field substantially increases spin diffusion and also affects the spin helix wavelength. (ii) In-plane magnetic fields applied in two perpendicular orientations allow for the extraction of the individual spin–orbit coupling parameters. (iii) Finally, we explore the influence of optical doping on the spin helix in a CdTe quantum well. Most importantly, a non-uniform spatio-temporal precession pattern is observed. The kinetic theory of spin diffusion allows us to model this finding by incorporating a dependence on the photo-carrier density into the Rashba and the Dresselhaus parameters. [ABSTRACT FROM AUTHOR]

We calculated the electronic structure, magnetism and optical properties of the Sc-doped, Y-doped, and (Sc, Y)-codoped anatase TiO 2 (101) surface using a projector augmented wave (PAW) method with GGA + U approximation. Sixteen doping systems were considered in the present work. The lattice distortion results in the generation of an internal local electric field. In addition, the difference between positive and negative spin charge densities leads to the generation of magnetism. With the exception of the Sc@in2 system, the width of band gap of the other doping systems increases to varying degrees, leading to a blueshift of the absorption edge. The photocatalytic activity of all the doping systems was improved to different degrees. The absorption intensity and absorption range of the Sc@in2&Y@O13 system in the visible-light region is the highest amongst all doping systems. This mainly attributed to the formation of hole states and the presence of impurity bands. • Lattice distortion can result in the generation of local electric fields. • The Sc@Ti5&Y&Ti6 mainly induce polarization of O-2p spin electrons and less induce polarization of Ti-3d spin electrons. • Except for Sc@in2, the width of band gap of the other doping systems increases to varying degrees. • The absorption intensity and absorption range of Sc@in2&Y@O13 is the highest amongst all doping systems. [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]

We use the technique of time-resolved Kerr rotation (TRKR) to measure the electron spin polarization generated by optical spin pumping in an n-type gallium arsenide (GaAs) epilayer when an external electric field is simultaneously applied on the sample. The drift of the electron spins under the influence of the external electric field is captured with spatial scans of the pump–probe separation. A significant decay in the magnitude of electron spin polarization with electric field is observed and is attributed to the increased inhomogeneous broadening caused by the field-induced drift and the hot electron effects. We extend the electric field range to as high as the Gunn threshold field in the measurement and we do not observe a spin amplification effect due to the spin Gunn effect under our experimental scheme. • Optical pump–probe technique is used to study electron spin polarization in n-GaAs. • E-field dependent spin drift and spin decay are measured in spin drag experiments. • Spin decay and amplification effects at E-fields at Gunn threshold regime are probed. [ABSTRACT FROM AUTHOR]

Non-spin-polarized electronic structures and Fermi surface properties of RX 2 Al 20 ( R  =  La, Ce, Yb, Th, U; X  = Ti, V, Cr, Mn) intermetallic compounds were calculated using the full potential all-electron local orbital (FPLO) approach in the framework of the local density approximation (LDA). Trends of the magnetism are discussed in terms of the characteristics of X - 3 d bands with a quantitative analysis of the relationship between band electron filling and crystal electric field splitting. Since coordination icosahedra of X -atoms have small trigonal distortion, crystal electric field splits the fivefold degenerate X -3 d state into low-energy singlet a 1 g and two higher-energy doublets e g . In R Ti 2 Al 20 and R V 2 Al 20 the population of the related 3 d sub-band is not sufficient to cause energetically favorable spin polarization, whereas magnetic instabilities develop in the R Cr 2 Al 20 series. Finally, a manifestation of strong repulsive interactions between itinerant Mn- d electrons become most pronounced in ferromagnetic UMn 2 Al 20 . The influence of non-magnetic R - f states on magnetic and thermodynamic properties is discussed with special emphasis on the role of the f – p and f – d hybridization. For LaTi 2 Al 20 and LaV 2 Al 20 the calculated quantum oscillation frequencies are in accord with experimental reports. [ABSTRACT FROM AUTHOR]

Using the tight-binding formalism, we explore the effect of weak disorder upon the conductance of zigzag edge silicene nanoribbons (SiNRs), in the limit of phase-coherent transport. We find that the fashion of the conductance varies with disorder, and depends strongly on the type of disorder. Conductance dips are observed at the Van Hove singularities, owing to quasilocalized states existing in surface disordered SiNRs. A conductance gap is observed around the Fermi energy for both edge and surface disordered SiNRs, because edge states are localized. The average conductance of the disordered SiNRs decreases exponentially with the increase of disorder, and finally tends to disappear. The near-perfect spin polarization can be realized in SiNRs with a weak edge or surface disorder, and also can be attained by both the local electric field and the exchange field. [ABSTRACT FROM AUTHOR]

First-principle calculations are used to investigate how an external electric field controls the spin polarization in graphene on chromia, a system of interest in the area of spin field-effect transistors. Both free-standing chromia thin films and graphene-bilayers are considered. The effect of the electric field depends on the thickness of the chromia and ranges from moderately strong and linear effects to very strong nonlinear magnetoelectricity. The graphene modifies and generally enhances the nonlinear magnetoelectric effect. We also find that the external electric field drastically changes the energy-dependent spin polarization in the graphene layers, which is predicted to reach values of up to about 80%. [ABSTRACT FROM AUTHOR]

The weak bulit-in electric field of BiOBr material is difficult to promote electron-hole separation, resulting in low photocatalytic CO 2 reduction performance. In this work, Ni has been successfully doped in unit cell of BiOBr and increase the unit cell dipole moment of BiOBr along the x, z directions from 0 to 0.04768 and 0.11293 eÅ, respectively. Enhancement of the unit cell dipole moment induces electron spin polarization near the Fermi energy level, which increases the surface potential from 18 mV to 36.2 mV. When the Ni doping ratio is 3 %, a higher carrier separation efficiency is achieved. 3 %Ni-BiOBr has the excellent CO 2 photoreduction performance with CO yield of 378.7 μmolg−1h−1, which is 4.3 times higher than pure BiOBr (86.75 μmolg−1h−1). Briefly, this research work throws light on enhancing built-in electric field by increasing unit cell dipole moment and inducing spin polarization for improving the photocatalytic performance. [Display omitted] • Ni doping into BiOBr increases the dipole moment and induce the spin polarization to enhance built-in electric field. • 3 %Ni-BiOBr CO 2 photoreduction performance with CO yield is 378.7 μmolg−1h−1. • The CO 2 photoreduction mechanism of 3 %Ni-BiOBr with enhanced electric field is proposed. [ABSTRACT FROM AUTHOR]

In this work, we present a detailed investigation of the influences of intrinsic spin-orbit coupling (ISOC) as well as Rashba spin-orbit coupling (RSOC) on the spin-resolved transport properties and net spin polarization of molybdenum disulfide (MoS 2 ) nanoribbons including different configurations. For this reason, we generalize the tight-binding model by including the effects of the ISOC on all the atoms and a RSOC induced by a vertical electric field. The results predict a noticeable spin polarization in along to the field for the armchair MoS 2 nanoribbon close to the Fermi level, which is originated mostly from edge states. Where as, the induced spin polarization in the zigzag MoS 2 ribbons is much smaller than that of the considered armchair ones. Contrary to the RSOC, which it can not introduce significant spin polarization in the ZMoS 2 the ribbon with width about 1–2 nm, the combination effect of an exchange field and Rashba spin-orbit interaction induces a spin-selective current especially close to the Fermi level. The numerical results may be useful to engineer and design magnetic-field-free spintronic devices based on the MoS 2 nanoribbons. [ABSTRACT FROM AUTHOR]

We investigate the spin-polarized transport properties for magnetic junctions consisting of two ferromagnetic bilayer graphene (FBG) electrodes separated by a fourth-generation Thue-Morse bilayer graphene superlattice (TMBGS) or the corresponding periodic bilayer graphene superlattice (PBGS) under a uniform electric field. The spin conductance, spin polarization, and tunneling magnetoresistance (TMR) of the FBG/TMBGS/FBG junction are numerically calculated and compared with those of the FBG/PBGS/FBG junction. We find that the spin conductance can be greatly changed not only by the magnetization of the two FBG electrodes, but also by the exchange splitting energy. In the low energy range, the spin polarization and the TMR show drastic oscillations with increasing the Fermi energy. In the high energy range, the spin polarization and the TMR tend to be zero as the Fermi energy increases. Furthermore, compared to the FBG/PBGS/FBG junction, in the FBG/TMBGS/FBG junction, relatively large values of the TMR can be more easily obtained as the bias voltage increases. [ABSTRACT FROM AUTHOR]

Noncovalent interactions between molecules are key for many biological processes. Necessarily, when molecules interact, the electronic charge in each of them is redistributed. Here, we show experimentally that, in chiral molecules, charge redistribution is accompanied by spin polarization. We describe how this spin polarization adds an enantioselective term to the forces, so that homochiral interaction energies differ from heterochiral ones. The spin polarization was measured by using a modified Hall effect device. An electric field that is applied along the molecules causes charge redistribution, and for chiral molecules, a Hall voltage is measured that indicates the spin polarization. Based on this observation, we conjecture that the spin polarization enforces symmetry constraints on the biorecognition process between two chiral molecules, and we describe how these constraints can lead to selectivity in the interaction between enantiomers based on their handedness. Model quantum chemistry calculations that rigorously enforce these constraints show that the interaction energy for methyl groups on homochiral molecules differs significantly from that found for heterochiral molecules at van der Waals contact and shorter (i.e., -0.5 kcal/mol at 0.26 nm). [ABSTRACT FROM AUTHOR]

[Display omitted] • Effects of the vacancy is mainly depended upon edge configuration of the ribbon. • Half-metallicity can be realized in zigzag BPNR with phosphorus vacancy. • Charge injection and transverse electric field can raise spin-polarization with B-vacancy. • Perfect bipolar spin filtering effect observed with a B-vacancy near rich-P edge. Edge states and vacancy-induced defect states simultaneously occur near Fermi level of boron-phosphide nanoribbon (BPNR) when there is a vacancy in it, which is a compromise of two important influencing factors for electronic property modulation. Based on density functional theory, the effects of mono-vacancy on electronic structure of zigzag/armchair BPNRs have been investigated. Calculation results indicate that effects of the vacancy on electronic property of the system is mainly depended on edge configuration of the ribbon. Half-metallicity can be realized in zigzag BPNR with phosphorus vacancy. Furthermore, it is found that charge injection and transverse electric field can raise spin-polarization of zigzag BPNR with boron vacancy near rich-B edge. Most interestingly, it exhibits perfect bipolar spin filtering effect for the case of zigzag BPNR with a boron vacancy near rich-P edge. [ABSTRACT FROM AUTHOR]

Phosphorene has attracted great interest in spintronics. Here, the electronic structures of monolayer zigzag black phosphorene nanoribbons(ZBPNRs) are researched. We found that the magnetic ground state of ZBPNRs is dependent on nanoribbon widths. In addition, we examine the role of the surface adatoms including Li, Na, K, Mg, Ca and Al in modifying the electronic properties of ZBPNRs. Our calculations show that the adsorption systems with Li, Na and K are half-metals due to the localization of transferred charge. On the other hand, Mg, Ca and Al, which provide more valence electrons than Li, Na and K, result in a smaller net magnetic moment and prefer semiconductor or metal. Our findings propose a new approach without magnetic atoms, magnetic field and strong electric field to realize half-metal in phosphorene, which overcome the drawbacks of graphene/silicene with negligible band-gap as well as transition metal sulfide with low carrier mobility. [ABSTRACT FROM AUTHOR]

Applying a transverse electric field, we theoretically explore the control of electron-spin filter based on layered semiconductor nanostructure-InSb/In x Ga 1-x As. Because of the electric field dependent effective potential of electron, not only size of spin polarization ratio but also its sign can be manipulated by changing magnitude or direction of applied electric field. An electrically-tunable electron-spin filter can be achieved for spintronics device applications. • Spin polarized transport is studied for electrons through InSb/In x Ga 1-x As/GaSb under a transverse electric field. • Electron-spin polarization is sensitive to applied electric field. • Both magnitude and sign of the spin polarization can be controlled by changing strength or direction of transverse electric field. • This layered semiconductor nanostructure can serve as an electrically-controllable electron-spin filter for spintronics device applications. [ABSTRACT FROM AUTHOR]

We evaluate the spin polarization (Edelstein or inverse spin galvanic effect) and the spin Hall current induced by an applied electric field by including the weak localization corrections for a two-dimensional electron gas. We show that the weak localization effects yield logarithmic corrections to both the spin polarization conductivity relating the spin polarization and the electric field and to the spin Hall angle relating the spin and charge currents. The renormalization of both the spin polarization conductivity and the spin Hall angle combine to produce a zero correction to the total spin Hall conductivity as required by an exact identity. Suggestions for the experimental observation of the effect are given. [ABSTRACT FROM AUTHOR]

Based on a novel magnetic nanostructure with zero average magnetic field, a spin spatial splitter was recently proposed. This paper reports on how to effectively manipulate this device using a transverse electrical field with an applied bias. With the help of the stationary phase method, the lateral displacement and its spin polarization are calculated for the electron across this device. Both magnitude and sign of spin polarization are found to vary sensitively with this applied electric field. Thus, this device can be controlled conveniently by electric means, and can consequently serve as an electrically-tunable spin spatial splitter for spintronics applications. [ABSTRACT FROM AUTHOR]

In order to achieve a controllable spin-polarized source, we have applied a transverse electric field to a spin filter based on a novel magnetic nanostructure with zero average magnetic field. We have analytically calculated the transmission coefficient, conductance and spin polarization for electrons to transit the device in the presence of a transverse electric field. The results demonstrate that the transmission, the conductance and the spin polarization vary sensitively with the electric field. It is shown that the performance of the spin filter can be manipulated expediently by adjusting the transverse electric field. Thus, the spin filter can be utilized as an electrically controllable spin-polarized source for spintronics applications. [ABSTRACT FROM AUTHOR]

We study spin-dependent electron transport properties of zigzag silicene nanoribbons in the presence of anti-ferromagnetic exchange field using a nonequilibrium Green׳s function method. Applying a transverse electric field, spin splitting can take place and the silicene nanoribbon can work as a spin filter. The spin polarization is calculated and it is shown that the spin filtering is perfect and the spin states of electrons are fully coherent. The spin direction of transmitted electrons through the silicene filter can be easily controlled by changing the transverse electric field direction. Using Hubbard model, we take into account the electron–electron interaction and we find that although this interaction causes some changes in the electron conductance, it has no destructive effect on spin filtering properties. The effect of a single vacancy on electron transport is also investigated and it is found that, the vacancy causes to decrease the electron conductance; however, the spin-dependent properties remain the same. The vacancy in the near of the edges of nanoribbon has less destructive effect on electron conductance than that in the middle. [ABSTRACT FROM AUTHOR]

We evaluate the spin polarization (Edelstein or inverse spin galvanic effect) and the spin Hall current induced by an applied electric field by including the weak localization corrections for a two-dimensional electron gas. We show that the weak localization effects yield logarithmic corrections to both the spin polarization conductivity relating the spin polarization and the electric field and to the spin Hall angle relating the spin and charge currents. The renormalization of both the spin polarization conductivity and the spin Hall angle combine to produce a zero correction to the total spin Hall conductivity as required by an exact identity. Suggestions for the experimental observation of the effect are given. [ABSTRACT FROM AUTHOR]

The coupled kinetic equation for density and spin Wigner functions is derived including spin-orbit coupling, electric and magnetic fields, and self-consistent Hartree mean fields suited for SU(2) transport. The interactions are assumed to be with scalar and magnetic impurities as well as scalar and spin-flip potentials among the particles. The spin-orbit interaction is used in a form suitable for solid state physics with Rashba or Dresselhaus coupling, graphene, extrinsic spin-orbit coupling, and effective nuclear matter coupling. The deficiencies of the two-fluid model are worked out consisting of the appearance of an effective in-medium spin precession. The stationary solution of all these systems shows a band splitting controlled by an effective medium-dependent Zeeman field. The self-consistent precession direction is discussed and a cancellation of linear spin-orbit coupling at zero temperature is reported. The precession of spin around this effective direction caused by spin-orbit coupling leads to anomalous charge and spin currents in an electric field. Anomalous Hall conductivity is shown to consist of the known results obtained from the Kubo formula or Berry phases and a symmetric part interpreted as an inverse Hall effect. Analogously the spin-Hall and inverse spin-Hall effects of spin currents are discussed which are present even without magnetic fields showing a spin accumulation triggered by currents. The analytical dynamical expressions for zero temperature are derived and discussed in dependence on the magnetic field and effective magnetizations. The anomalous Hall and spin-Hall effect changes sign at higher than a critical frequency dependent on the relaxation time. [ABSTRACT FROM AUTHOR]

The spin and density response functions in the random phase approximation are derived by linearizing the kinetic equation including a magnetic field, the spin-orbit coupling, and mean fields with respect to an external electric field. Different polarizatio n functions appear describing various precession motions showing Rabi satellites due to an effective Zeeman field. The latter turns out to consist of the mean-field magnetization, the magnetic field, and the spin-orbit vector. The collective modes for charged and neutral systems are derived and a threefold splitting of the spin waves dependent on the polarization and spin- orbit coupling is shown. The dielectric function including spin-orbit coupling, polarization, and magnetic fields is presented analytically for long wavelengths and in the static limit. The dynamical screening length as well as the long-wavelength dielectric function shows an instability in charge modes, which are interpreted as spin segregation and domain formation. The spin response describes a crossover from damped oscillatory behavior to exponentially damped behavior dependent on the polarization and collision frequency. The magnetic field causes ellipsoidal trajectories of the spin response to an external electric field and the spin-orbit coupling causes a rotation of the spin axes. The spin-dephasing times are extracted and discussed in dependence on the polarization, magnetic field, spin-orbit coupling, and single-particle relaxation times. [ABSTRACT FROM AUTHOR]

We investigate charge conductance and spin and valley polarization along with the tunneling magnetoresistance (TMR) in silicene junctions composed of normal silicene and ferromagnetic silicene. We show distinct features of the conductances for parallel and antiparallel spin configurations and the TMR, as the ferromagnetic-normalferromagnetic junction is tuned by an external electric field. We analyze the behavior of the charge conductance and valley and spin polarizations in terms of the independent conductances of the different spins at the two valleys and the band structure of ferromagnetic silicene and show how the conductances are affected by the vanishing of the propagating states at one or the other valley. In particular, unlike in graphene, the band structures at the two valleys are independently affected by the spin in the ferromagnetic regions and lead to nonzero and, in certain parameter regimes, pure valley and spin polarizations, which can be tuned by the external electric field. We also investigate the oscillatory behavior of the TMR with respect to the strength of the barrier potential (both spin-independent and spin-dependent barriers) in the normal silicene region and note that in some parameter regimes, the TMR can even go from positive to negative values, as a function of the external electric field. [ABSTRACT FROM AUTHOR]

Spin polarized van der Waals (vdW) heterostructures have attracted considerable interest owing to the spin splitting manipulation. In this paper, first-principles calculations are employed to explore the two-dimensional arsenene/CrI 3 vdW heterostructure as a promising spin polarized material, as well as the spin polarization under strain and electronic field are investigated. The most stable stacking configuration and ferromagnetic (FM) property of the arsenene/CrI 3 vdW heterostructure have been confirmed. The detailed calculations show that the Curie temperature (T c) of the FM coupling CrI 3 layer in the heterostructure can be enhanced up to 61 K, which is attributed to both superexchange interaction and proximity exchange effect. The electronic structures suggest that this heterostructure possess an intrinsic type-II band alignment and diluted magnetic semiconductor property. Interestingly, we found a transition from diluted magnetic semiconductor to half-metal and gradually to metal induced by the biaxial strains, and the extra electronic field can modulate the "maxican hat" of the valance band maximum (VBM) of arsenene. Our work provides not only application prospects of the arsenene/CrI 3 vdW heterostructure nanodevices but also theoretical effective support for the research and development of the spin electronics and flexible electronics. • The arsenene/CrI 3 heterostructure possess an intrinsic type-II band alignment and diluted magnetic semiconductor property. • Biaxial strains can make arsenene/CrI 3 heterostructure transform from diluted magnetic semiconductor to half-metal and gradually to metal. • Electronic field can change the contribution of As and I atoms in VBM, enlarge the band gap. [ABSTRACT FROM AUTHOR]

In this paper, the spin-inversion properties and the current density expression for graphene superlattice with Rashba spin–orbit interaction (RSOI) in the presence of a constant electric field are studied. It is found that the angular range of the spin-inversion can be efficiently controlled by the number of barriers. In addition, the efficiency of spin-inversion decreases in the presence of electric field. As the number of barriers increases, the spin-dependent current density decreases. Furthermore, when an external electric field is present, the spin polarization can be observed, whereas for the RSOI alone it is zero. [ABSTRACT FROM AUTHOR]

We have investigated the electronic, magnetic, and optical properties of hydrogenated diamond nanowires (DNWs) with nitrogen-vacancy (NV) centers using density functional theory. The strong localization of defect states results in the formation of local magnetic moments with a spin-polarization energy that is close to those for transition-metal atoms. Such spin-polarized defect states are found to be stable well above room temperature, in agreement with previous experimental reports. In addition, we find that a semiconductor-metal transition can be triggered upon applying a transverse electric field. Furthermore, an enhanced optical absorption in the visible-light region is predicted in DNWs with NV centers. The strength and the position of the absorption can be tuned or optimized by an external electric field and/or the nanowire diameter. [ABSTRACT FROM AUTHOR]