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The response of crystal structure to external stimuli provides potential applications in the areas of detection, diagnosis, and repair. In this work, we fabricate two allotropic organic cocrystals, with different space groups and lattice parameters, with identical donor and acceptor molecules inside them. Under external stimuli, lattice vibration and electron-phonon coupling present pronounced differences in these two types of crystals, where different strengths of spin polarizations are observed. Furthermore, due to pronounced differences in coupling between lattice and spin inside the allotropic charge transfer crystals, the magnetic field presents a discrepant tunability on both transmission and fluorescence lifetimes. Through decreasing temperature or applying external electric field, the electron-phonon coupling coefficient presents a decreasing tendency, which will affect the dipole and dielectric constant in the allotropic crystals differently.

The water shortage crisis, characterized by organic micropollutants (OMPs), urgently requires new materials and methods to deal with it. Although heteroatom doping has been developed into an effective method to modify carbon nanomaterials for various heterogeneous adsorption and catalytic oxidation systems, the active source regulated by intrinsic electron and spin structures is still obscure. Here, a series of nonmetallic element-doped (such as P, S, and Se) covalent triazine frameworks (CTFs) were constructed and applied to remove organic pollutants using the adsorption-photocatalysis process. The external mass transfer model (EMTM) and the homogeneous surface diffusion model (HSDM) were employed to describe the adsorption process. It was found that sulfur-doped CTF (S-CTF-1) showed a 25.6-fold increase in saturated adsorption capacity (554.7 μmol/g) and a 169.0-fold surge in photocatalytic kinetics (5.07 h -1 ), respectively, compared with the pristine CTF-1. A positive correlation between electron accumulation at the active site (N1 atom) and adsorption energy was further demonstrated with experimental results and theoretical calculations. Meanwhile, the photocatalytic degradation rates were greatly enhanced by forming a built-in electric field driven by spin polarization. In addition, S-CTF-1 still maintained a 98.3% removal of 2,2',4,4'-tetrahydroxybenzophenone (BP-2) micropollutants and 97.6% regeneration after six-cycle sequencing batch treatment in real water matrices. This work established a relation between electron and spin structures for adsorption and photocatalysis, paving a new way to design modified carbon nanomaterials to control OMPs.

Experiments on spin transport through a chiral molecule demonstrated the attainment of significant spin polarization, demanding a theoretical explanation. We report the emergence of spin Fano resonances as a mechanism in the chiral-induced spin-selectivity (CISS) effect associated with transport through a chiral polyacetylene molecule. Initializing electrons through optical excitation, we derive the Fano resonance formula for the spin polarization. Computations reveal that quasidegeneracy is common in this complex molecular system. A remarkable phenomenon is the generation of pronounced spin Fano resonances due to the contributions of two near-degeneracy states. We also find that the Fano resonance width increases linearly with the coupling strength between the molecule and the lead. Our findings provide another mechanism to explain the experimental observations and lead to new insights into the role of the CISS effect in complex molecules from the perspective of transport and spin polarization resonance, paving the way for chiral molecule-based spintronics applications.

The helical distribution of the electronic density in chiral molecules, such as DNA and bacteriorhodopsin, has been suggested to induce a spin-orbit coupling interaction that may lead to the so-called chirality-induced spin selectivity (CISS) effect. Key ingredients for the theoretical modelling are, in this context, the helically shaped potential of the molecule and, concomitantly, a Rashba-like spin-orbit coupling due to the appearance of a magnetic field in the electron reference frame. Symmetries of these models clearly play a crucial role in explaining the observed effect, but a thorough analysis has been largely ignored in the literature. In this work, we present a study of these symmetries and how they can be exploited to enhance chiral-induced spin selectivity in helical molecular systems.

The effective mass at the Fermi level is measured in the strongly interacting two-dimensional (2D) electron system in ultra-clean SiGe/Si/SiGe quantum wells in the low-temperature limit in tilted magnetic fields. At low electron densities, the effective mass is found to be strongly enhanced and independent of the degree of spin polarization, which indicates that the mass enhancement is not related to the electrons' spins. The observed effect turns out to be universal for silicon-based 2D electron systems, regardless of random potential, and cannot be explained by existing theories. [ABSTRACT FROM AUTHOR]

To investigate the effects of the optical field and the Fermi velocity on the transport properties of spin and valley electrons, we impose a normal/ferromagnetic/normal (N/F/N) quantum structure based on the monolayer WSe 2. The results indicate that there is a strong switch effect for spin- and valley-related electrons. When left-handed off-resonant circularly polarized light is irradiated in the intermediate ferromagnetic region, 100 % polarization for K valley electrons can be achieved in the entire effective energy spectrum of the optical field. Meanwhile, 100 % polarization of the K ′ valley can also be gained with the right-handed off-resonant circularly polarized light in the junction. Moreover, the perfect polarization of spin-up electrons can be obtained when the ferromagnetic exchange field is applied to the structure. Additionally, the Fermi velocity barrier also changes the energy band of the studied material, which makes the spin and valley transport increase with the increase of the velocity barrier but does not produce spin or valley polarizations. These interesting results clarify that the optical field and the Fermi velocity both make a contribution to the modulation of spin electrons for the two valleys and provide a useful method for the design of novel spintronic and valleytronic devices. [ABSTRACT FROM AUTHOR]

We reply to the Comment by Donath et al. on our setup, which allows a total 3D control of the polarization direction of the electron beam in an inverse photoemission spectroscopy (IPES) experiment, a significant advance with respect to previous setups with partial polarization control. Donath et al. claim an incorrect operation of our setup after comparing their results, treated to enhance the spin asymmetry, with our spectra without the same treatment. They also equal spectra backgrounds instead of equaling peak intensities above the background. Thus, we compare our Cu(001) and Au(111) results with the literature. We reproduce previous results, including spin-up/spin-down spectral differences observed for Au and not observed for Cu. Also, spin-up/spin-down spectral differences appear at the expected reciprocal space regions. In the Comment, it is also stated that our tuning of the spin polarization misses the target because the spectra background changes when tuning the spin. We argue that the background change is irrelevant to IPES since the information is contained in peaks produced by primary electrons, those having conserved their energy in the inverse photoemission process. Second, our experiments agree with previous results from Donath et al. [Wissing et al., New J. Phys. 15, 105001 (2013)] and with a zero-order quantum-mechanical model of spins in vacuum. Deviations are explained by more realistic descriptions including the spin transmission through an interface. Consequently, the operation of our original setup is fully demonstrated. Our development corresponds to "the promising and rewarding angle-resolved IPES setup with the three-dimensional spin resolution," as indicated in the Comment, after our work. [ABSTRACT FROM AUTHOR]

Improving the efficiency of spin generation, injection, and detection remains a key challenge for semiconductor spintronics. Electrical injection and optical orientation are two methods of creating spin polarization in semiconductors, which traditionally require specially tailored p-n junctions, tunnel or Schottky barriers. Alternatively, we introduce here a novel concept for spin-polarized electron emission/injection combining the optocoupler principle based on vacuum spin-polarized light-emitting diode (spin VLED) making it possible to measure the free electron beam polarization injected into the III-V heterostructure with quantum wells (QWs) based on the detection of polarized cathodoluminescence (CL). To study the spin-dependent emission/injection, we developed spin VLEDs, which consist of a compact proximity-focused vacuum tube with a spin-polarized electron source (p-GaAs(Cs,O) or Na2KSb) and the spin detector (III-V heterostructure), both activated to a negative electron affinity (NEA) state. The coupling between the photon helicity and the spin angular momentum of the electrons in the photoemission and injection/detection processes is realized without using either magnetic material or a magnetic field. Spin-current detection efficiency in spin VLED is found to be 27% at room temperature. The created vacuum spin LED paves the way for optical generation and spin manipulation in the developing vacuum semiconductor spintronics. [ABSTRACT FROM AUTHOR]

The ferromagnetic and antiferromagnetic wave functions of the KMnF3 perovskite have been evaluated quantum‐mechanically by using an all electron approach and, for comparison, pseudopotentials on the transition metal and the fluorine ions. It is shown that the different number of α and β electrons in the d shell of Mn perturbs the inner shells, with shifts between the α and β eigenvalues that can be as large as 6 eV for the 3s level, and is far from negligible also for the 2s and 2p states. The valence electrons of F are polarized by the majority spin electrons of Mn, and in turn, spin polarize their 1s electrons. When a pseudopotential is used, such a spin polarization of the core functions of Mn and F can obviously not take place. The importance of such a spin polarization can be appreciated by comparing (i) the spin density at the Mn and F nuclear position, and then the Fermi contact constant, a crucial quantity for the hyperfine coupling, and (ii) the ferromagnetic–antiferromagnetic energy difference, when obtained with an all electron or a pseudopotential scheme, and exploring how the latter varies with pressure. This difference is as large as 50% of the all electron datum, and is mainly due to the rigid treatment of the F ion core. The effect of five different functionals on the core spin polarization is documented. [ABSTRACT FROM AUTHOR]

In this paper, we theoretically investigate how to control spin filtering via a δ -doping for electrons in a magnetically and electrically modulated semiconductor nanostructure (MEMSN), which can be realized by patterning a ferromagnetic (FM) stripe and a Schottky-metal (SM) stripe on top and bottom of GaAs/AlxGa 1 − x As heterostructure in experiments, respectively. A considerable spin filtering effect still exists because of spin–orbit coupling (SOC), even if a δ -doping is included. Moreover, spin polarization ratio can be manipulated by δ -doping, which may lead to a structurally-controllable electron-spin filter for semiconductor spintronics. [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]

A new spin- and angle-resolved inverse photoemission setup with a low-energy electron source is presented. The spin-polarized electron source, with a compact design, can decouple the spin polarization vector from the electron beam propagation vector, allowing one to explore any spin orientation at any wavevector in angle-resolved inverse photoemission. The beam polarization can be tuned to any preferred direction with a shielded electron optical system, preserving the parallel beam condition. We demonstrate the performances of the setup by measurements on Cu(001) and Au(111). We estimate the energy resolution of the overall system at room temperature to be ∼170 meV from kBTeff of a Cu(001) Fermi level, allowing a direct comparison to photoemission. The spin-resolved operation of the setup has been demonstrated by measuring the Rashba splitting of the Au(111) Shockley surface state. The effective polarization of the electron beam is P = 30% ± 3%, and the wavevector resolution is ΔkF ≲ 0.06 Å−1. Measurements on the Au(111) surface state demonstrate how the electron beam polarization direction can be tuned in the three spatial dimensions. The maximum of the spin asymmetry is reached when the electron beam polarization is aligned with the in-plane spin polarization of the Au(111) surface state. [ABSTRACT FROM AUTHOR]

We have investigated the spin-induced voltage in the Hanle effect and the spin polarization factor of electrons in lateral spin devices based on InSb semiconductors with different electron concentrations. It is found that with increasing electron concentration, both the voltage and the polarization factor decrease. [ABSTRACT FROM AUTHOR]

The synergistic effect of the carrier velocity and density is studied to understand chirality-induced spin selectivity (CISS) in helical spin-filtering devices. Unlike most previous theories that emphasize the asymmetry between the transmitted spin-related electron densities, we reveal two types of dynamics for the spin polarization: (i) spin conversion dynamics between spin-up and spin-down electrons and (ii) spin-dependent transport dynamics leading to different propagation velocities of spin-up and spin-down electrons. The former dominate in the high-bias-voltage regime by electron tunneling, while the latter dominate in the low-bias-voltage regime by polaron transport. Our theory reproduces well the recently observed extreme spin polarization under a certain bias voltage in a helical spin-filtering device, and it provides a general microscopic perspective for reconsidering CISS. [ABSTRACT FROM AUTHOR]

Using results from atomic spectroscopy, we show that there are two types of flat-planes conditions. The first type of flat-planes condition occurs when the energy as a function of the number of electrons of each spin, Nα and Nβ, has a derivative discontinuity on a line segment where the number of electrons, Nα + Nβ, is an integer. The second type of flat-planes condition occurs when the energy has a derivative discontinuity on a line segment where the spin polarization, Nα - Nβ, is an integer, but does not have a discontinuity associated with an integer number of electrons. Type 2 flat planes are rare-we observed just 15 type 2 flat-planes conditions out of the 4884 cases we tested-but their mere existence has implications for the design of exchange-correlation energy density functionals. To facilitate the development of functionals that have the correct behavior with respect to both fractional number of electrons and fractional spin polarization, we present a dataset for the chromium atom and its ions that can be used to test new functionals. [ABSTRACT FROM AUTHOR]

A metallic state with a vanishing activation gap, at a filling factor ν = 8 / 5 in the untilted specimen with n = 2 × 10 11 c m - 2 , and at ν = 4 / 3 at n = 1.2 × 10 11 c m - 2 under a θ = 66 0 tilted magnetic field, is examined through a microwave photo-excited transport study of the GaAs/AlGaAs 2 dimensional electron system (2DES). The results presented here suggest, remarkably, that at the possible degeneracy point of states with different spin polarization, where the 8/5 or 4/3 FQHE vanish, there occurs a peculiar marginal metallic state that differs qualitatively from a quantum Hall insulating state and the usual quantum Hall metallic state. Such a marginal metallic state occurs most prominently at ν = 8 / 5 , and at ν = 4 / 3 under tilt as mentioned above, over the interval 1 ≤ ν ≤ 2 , that also includes the ν = 3 / 2 state, which appears perceptibly gapped in the first instance. [ABSTRACT FROM AUTHOR]

We theoretically investigate dwell time for electrons in a magnetic nanostructure with a δ -doping, which is formed on InAs / Al x In 1 − x As heterostructure by depositing a ferromagnetic (FM) stripe. We find that dwell time depends strongly on electron-spins owing to Zeeman coupling and broken symmetry. We also demonstrate that spin-polarized dwell time can be manipulated by δ -doping. Thus, electron spins can be separated in time dimension and such a magnetic nanostructure can be employed as a structurally-controllable temporal spin splitter for spintronics device applications. [ABSTRACT FROM AUTHOR]

To analyze the contributions of the metal atoms to stabilize and synthesize the small cage-like carbon clusters, the configurations, electronic and magnetic characteristics of Mn-, Fe-, Co- and Ni-substituted C 2 0 cage have been investigated using the PBE functional. The results demonstrate that the TM (TM = Mn, Fe, Co and Ni) substitution decreases the structural stability of the C 2 0 cages, while increases the activity of the C 2 0 cages. Electronic migrations between the TM atoms and C atoms are less. All the TM–C bonds of the TMC 1 9 and TM2C 1 8 clusters display covalent bond characters. The 3 s orbitals of TM atoms lose electrons, the 3 d and 4 p orbitals of TM atoms obtain electrons. The special distributions of the HOMO states of the TMC 1 9 and TM2C 1 8 clusters are mainly from the hybridization of the C p orbitals and the TM d orbitals. The Mn2C 1 8 cages display the highest spin polarization. [ABSTRACT FROM AUTHOR]

We study the spin-orbit interaction of two-dimensional electron/hole gas (2DEGs/2DHGs) on quasi-2D potassium niobates (KNs) via first-principles calculations. The strong surface polarity changes the free surface states from 2DEGs to 2DHGs. The in-plane dipole maintained on 2D models leads to giant Zeeman-type spin splitting, as high as 566 meV for the (001)c facet KN and 1.21 eV for the (111)c facet KN. The thickness-dependent Zeeman-type spin splitting shows a linear relation with respect to 1/r, while the corresponding in-plane polarization quantum has a linear relation of 1/(2^0.5)with respect to a decrease in thickness. Interestingly, the 2DHGs with molecular-like orbital character is solely constituted by O 2p states, showing logic switchable behavior at extremely thin samples with enormous Zeeman-type splitting that can switch between insulator and conductor by opposite spin polarization. [ABSTRACT FROM AUTHOR]

The helical distribution of the electronic density in chiral molecules, such as DNA and bacteriorhodopsin, has been suggested to induce a spin-orbit coupling interaction that may lead to the so-called chirality-induced spin selectivity (CISS) effect. Key ingredients for the theoretical modelling are, in this context, the helically shaped potential of the molecule and, concomitantly, a Rashba-like spin-orbit coupling due to the appearance of a magnetic field in the electron reference frame. Symmetries of these models clearly play a crucial role in explaining the observed effect, but a thorough analysis has been largely ignored in the literature. In this work, we present a study of these symmetries and how they can be exploited to enhance chiral-induced spin selectivity in helical molecular systems. [ABSTRACT FROM AUTHOR]

The compressibility was calculated of electrons as a function of external magnetic, temperature and carrier density in the parabolic lateral barrier quantum wires (QWRs). The compressibility found by using Seitz's theorem in which electron self-energy is calculated within the random-phase approximation. All results for GaAs QWRs show that a large difference between the compressibility in low- and high-temperature region at external magnetic fields. These results can help clarify how the Coulomb interaction and exchange, correlation energy affect the compressibility of the semiconductor across a wide range of density, temperature, and external magnetic. • Spin, temperature, and carrier density dependence of electron compressibility in quantum wires is analyzed. • Compressibility increases with external magnetic and temperature. • Compressibility has a clear minimum at low every external magnetic an at low carrier density below 1*106 cm−1. • The results are consistent with experimental results. [ABSTRACT FROM AUTHOR]

The structural, elastic, electronic, and magnetic properties of Sr2CrMoO6 have been studied using first-principles calculations based on the full-potential linearized augmented plane-wave method. Spin-polarized local density approximation (LDA) is adopted to treat the exchange-correlation electron interactions. Our optimized structural parameters are in good agreement with other theoretical and experimental parameters available in the literature. The studied compound is elastically ductile and anisotropic. To obtain more accuracy in the results of the electronic and magnetic properties, the Hubbard-corrected LDA (LDA+U) and Tran–Blaha modified Becke–Johnson (mBJ) exchange potentials are also employed, which predict the half-metallicity with a perfect spin polarization of 100% in Sr2CrMoO6, whereas it is only nearly half-metallic as calculated by the LDA. The half-metallic band gaps obtained through mBJ and LDA+U are 2.374 eV and 1.980 eV, respectively. The magnetic results show the antiferromagnetic interactions between the Cr3+ and Mo5+ ions, whereas the contribution of the Sr2+ and O2− ions are negligible. [ABSTRACT FROM AUTHOR]

In recent years, the search for new Dirac half-metallic materials has been one of the hotspots in the field of spintronics because they have very good physical properties, such as massless Dirac fermions and full spin polarization. In this study, using density function theory combined with the quasi-harmonic Debye model, we show that perovskite-type dysprosium manganite is a novel half metal with multiple Dirac cones. A detailed study of the electronic, magnetic, and thermodynamic properties of DyMnO 3 was carried out. Furthermore, the effects of uniform strain, the on-site Coulomb interaction U , spin-orbit coupling, and hole and electron doping on the multiple Dirac cones and full spin polarization were investigated. We should point out that such a spin-polarized Dirac material is rare among perovskite-type compounds. Hence, we hope that, through this work, this kind of material will receive more extensive attention in future studies. In this study, using density function theory combined with the quasi-harmonic Debye model, we show that perovskite-type dysprosium manganite is a novel half metal with multiple Dirac cones. Moreover, in order to test whether the material has a long spin coherence length, we studied the effect of SOC on the band structure. Image 1 [ABSTRACT FROM AUTHOR]

Highlights • The change of sign of anomalous of permalloy film was observed. • The modulation of anomalous Hall effect by oxide in permalloy was found. • The spin accumulation induced by AHE was explored in a multilayer structure. Abstract We report that the unusual behavior of anomalous Hall effect (AHE) in permalloy (Fe 20 Ni 80 , Py) thin film with silicon oxide (SiO 2) as an adjacent layer. It is found that sign of AHE changes from positive to negative with decrement in thickness of Py. Through the AHE measurement, we demonstrate that this unusual behavior originates from the interface of Py/SiO 2 rather from the structural inversion asymmetry. In the Pt/YIG/Cu/Py/SiO 2 multilayer structure with a charge current injected in the Py layer, the information on spin accumulation at the YIG/Cu interface induced by the AHE in Py, can be obtained from the nonlocal voltage measured in the Pt layer. Through the nonlocal measurement, it is found, however, the electrons with same spin for interfacial Py near the SiO 2 layer and bulk Py are scattered to the same direction. Hence we can deduce that the sign of spin polarization of the conductivity closely related to the asymmetry in density of states at the Fermi level for interfacial Py and bulk Py should be opposite to each other, which is responsible for the abnormal AHE observed. Our results demonstrate that oxide layer can drive the change of sign of AHE of Py, which provide an alternative way of manipulating the spin-related transport. [ABSTRACT FROM AUTHOR]

In this paper, we theoretically investigate how to control electron-spin polarization by δ-doping in a both magnetically and electrically confined semiconductor heterostructure. It is shown that, due to Zeeman coupling, a considerable spin polarization effect appears in the δ-doped device. It is also shown that both magnitude and sign of spin polarization can be tuned by changing weight or position of the δ-doping. Thus, a δ-doping controllable spin filter can be achieved for spintronics device applications. [ABSTRACT FROM AUTHOR]

We investigated the electronic and magnetic properties of KCuF3 and KCu0.875Mg0.125F3 crystals by means of Density Functional periodic computations at the B3LYP level of theory. We considered four possible magnetic ordering of the unpaired electrons on copper ions. Both materials are correctly predicted as being 1D antiferromagnetic insulators, and the superexchange parameters in the crystallographic ab planes and along the c direction measure +10 and -600 K, respectively. Residual spin polarization is found also on fluorine atoms, in agreement with literature results. We found a complete orbital ordering at Cu sites: in the copper reference frame dxy, dyz, dxz, and dz2 orbitals contain about 2 electrons each, while the dx2-y2 orbital is only partially filled. The perturbation induced by doping of KCuF3 with Mg is very strong and localized on the first shell of F neighbours. Mg has a very small influence on the ordering of the 3d orbitals of copper and on the Cu-Cu magnetic superexchange parameters but reduces significantly the absolute energy differences between the antiferromagnetic ground state and the ferromagnetic phase, in agreement with the experiment. The absence of long range effects makes Mg a suitable dopant for the investigation of strongly correlated electronic systems by means of orbital dilution. [ABSTRACT FROM AUTHOR]

Differential cross sections and polarization correlations for the scattering of relativistic spin-polarized leptons from unpolarized ground-state sodium nuclei are calculated within the distorted-wave Born approximation (DWBA). Various nuclear ground-state charge distributions are probed. Besides potential scattering, also electric C2 and magnetic M1 and M3 transitions are taken into account. It is shown that even for a light nucleus such as 23 Na there are considerable electron–positron differences at high collision energies and large scattering angles. In particular, the symmetry of the Sherman function with respect to a global sign change, as predicted by the second-order Born approximation when replacing electrons by positrons, is broken whenever the diffraction structures come into play beyond 100 MeV. [ABSTRACT FROM AUTHOR]

We theoretically investigate the electron transport properties in a nanostructure modulated by a ferromagnetic stripe (FM) and a Schottky metal stripe (SM) as well as a δ-doping with the help of transfer-matrix method. It is found that the position and the weight of the δ-doping, the width of the SM and the electrical potential, all play an important role in the electron transmission probability and the spin polarization. Therefore, we can control the electron transport properties through adjusting the SM and the δ-doping. These interesting phenomena may be very helpful for designing the spintronic devices. [ABSTRACT FROM AUTHOR]

An accurate expression for the exchange-correlation free energy f xc of homogeneous electron fluids at finite temperatures is presented on the basis of Singwi-Tosi-Land-Sjölander ( STLS) approximation. In addition to the derivation for the paramagnetic state, that for the ferromagnetic state is carried out afresh in which a correction in the strong Coulomb coupling regime is incorporated into the construction of the analytic expression as a function of the coupling constant and Fermi degeneracy. The fitting formula for f xc is then extended over any degree of spin polarization with the aid of available interpolation scheme. The proposed equation of state, called the iSTLS formula, shows reasonable agreement with the existing quantum Monte Carlo evaluations at finite temperatures in the paramagnetic state, thus giving a consensus for the thermodynamic functions between many-body theories and computer simulations. On the other hand, the current status for the agreement between various evaluations of f xc is relatively unsatisfactory in the ferromagnetic state, suggesting the necessity for further investigations. [ABSTRACT FROM AUTHOR]

Spin-polarized density functional theory (DFT) computations have been carried out to investigate Cr-, B-doping as well as codoping in the SrTiO 3 crystal. Impact of the oxygen vacancy as an intrinsic point defect has been also taken into consideration. In order to describe more precisely 3 d electrons of the Ti and Cr atoms, Hubbard-like U term in the DFT has been introduced. Outcomes of the calculations reveal occupied states within the forbidden energy region arguing that these in-gap states might be responsible for visible light photocatalysis in the SrTiO 3 . Structural and magnetic features of the doped and codoped material are discussed as well. [ABSTRACT FROM AUTHOR]

[Display omitted] • The N -doped coralline Co 9 S 8−x N x catalyst possessed filamentous porous structures. • ∼100 % degradation efficiency of AMT was achieved in 120 min. • Electrons redistribution and charge transfer mechanisms of Co 9 S 8−x N x were revealed. Improving the recalcitrant emergent contaminant removal in electron-Fenton (EF) has been one of the focal problems. Here, a N -doped coralline Co 9 S 8−x N x catalyst was synthesized with high electronegativity and strong spin polarization for promoting the H 2 O 2 generation efficiency and Amitriptyline (AMT) removal. After doping nitrogen, catalytic performance of Co 9 S 8−x N x has increased ∼10 % on AMT decay and the treatment time was shortened ∼40 min. Co 9 S 8−x N x induced 2-electron oxygen reduction reaction (ORR) mechanism has also been investigated. According to electronic structure analysis, electrons surrounding the cobalt atoms were redistributed and the π* orbitals of *O 2 were occupied asymmetrically forcing *O 2 to be of radical nature active for hydrogenation, which significantly reduced required absorption energy in the rate-determining step (RDS). This work clarifies the mediate role of N -doped activating delocalized electron of adjacent atoms on the surface of Co 9 S 8−x N x and also gives new insights into the rational design of catalyst for refractory pollutant degradation in wastewater. [ABSTRACT FROM AUTHOR]

We investigate spin-dependent tunneling time, dwell and group delay time, through monolayer graphene barrier with Rashba spin–orbit interaction in the presence of zigzag and armchair direction strain. It is found that the oscillation amplitude of the dwell time increases by increasing the strain strength. In addition, for the zigzag direction strain the Hartman effect can be observed for the both spin-up and spin-down electrons. When the armchair direction strain is applied to a monolayer graphene the spin polarization increases with increasing the strain strength, whereas for the zigzag direction strain it is zero. In this case, unlike the zigzag direction strain dwell time for the normal incident angle depends on the spin state of electron. [ABSTRACT FROM AUTHOR]

In spintronics, identifying an effective technique for generating spin-polarized current has fundamental importance. The spin-filtering effect across a ferromagnetic insulating layer originates from unequal tunneling barrier heights for spin-up and spin-down electrons, which has shown great promise for use in different ferromagnetic materials. However, the low spin-filtering efficiency in some materials can be ascribed partially to the difficulty in fabricating high-quality thin film with high Curie temperature and/or partially to the improper model used to extract the spin-filtering efficiency. In this work, a new technique is successfully developed to fabricate high quality, ferrimagnetic insulating γ-Fe2O3 films as spin filter. To extract the spin-filtering effect of γ-Fe2O3 films more accurately, a new model is proposed based on Fowler-Nordheim tunneling and Zeeman effect to obtain the spin polarization of the tunneling currents. Spin polarization of the tunneled current can be as high as −94.3% at 2 K in γ-Fe2O3 layer with 6.5 nm thick, and the spin polarization decays monotonically with temperature. Although the spin-filter effect is not very high at room temperature, this work demonstrates that spinel ferrites are very promising materials for spin injection into semiconductors at low temperature, which is important for development of novel spintronics devices. [ABSTRACT FROM AUTHOR]

A theoretical model is presented in this paper for degree of spin polarization in a light emitting diode (LED) whose epitaxial region contains quantum dots doped with magnetic impurity. The model is then used to investigate the effect of electron-phonon interaction on degree of spin polarization at different temperatures and magnetic fields. It is found that magnetic impurity increases the degree of spin polarization irrespective of temperature, while the electron-phonon interaction decreases the degree of spin polarization. Results are found to be in better agreement with experiments. [ABSTRACT FROM AUTHOR]

When spin-polarized electrons are reflected at a ferromagnetic surface, their spin-polarization vector exhibits a spin motion, comprised of an azimuthal precession and a polar rotation about the magnetization direction of the ferromagnetic material. It is shown that the angles of precession and of rotation are intimately related by dispersion relations. Comparison with experimental data verifies their applicability. Particular attention has to be paid to the presence of complex zeros of the spin-dependent electron reflectivity. [ABSTRACT FROM AUTHOR]

• Dwell time is evaluated for electron in the EMEBN device. • Electron spins can be separated in time dimension. • Spin polarization is modulated by properly constructing SM stripe. • A temporal spin splitter is proposed for semiconductor spintronics. We calculate dwell time of electron in magnetically and electrically confined semiconductor nanostructure (MECSN), which can be experimentally fabricated by patterning a ferromagnetic (FM) stripe and a Schottky metal (SM) stripe on top and bottom of InAs/Al x In 1-x As, respectively. Spin-dependent dwell time is found thanks to the Zeeman interaction, which gives rise to the separation of electron spins in time dimension. Properly patterning the SM stripe can obviously improve electron-spin polarization owing to the SM-stripe dependence of effective potential experienced by electron in the MECSN, achieving a tunable temporal spin splitter for semiconductor spintronics device applications. [ABSTRACT FROM AUTHOR]

We propose a method to compute the transmission through correlated heterostructures by combining density functional and many-body dynamical mean field theories. The heart of this combination consists in porting the many-body self-energy from an all electron basis into a pseudopotential localized atomic basis set. Using this combination we study the effects of local electronic interactions and finite temperatures on the transmission across the Cu4CoCu4 metallic heterostructure. It is shown that as the electronic correlations are taken into account via a local but dynamic self-energy, the total transmission at the Fermi level gets reduced (predominantly in the minority-spin channel), whereby the spin polarization of the transmission increases. The latter is due to a more significant d-electron contribution, as compared to the noncorrelated case in which the transport is dominated by s and p electrons. [ABSTRACT FROM AUTHOR]

The ground-state energy, electron density, and related properties of ordinary matter can be computed efficiently when the exchange-correlation energy as a functional of the density is approximated semilocally. We propose the first meta-generalized-gradient approximation (meta-GGA) that is fully constrained, obeying all 17 known exact constraints that a meta-GGA can. It is also exact or nearly exact for a set of "appropriate norms," including rare-gas atoms and nonbonded interactions. This strongly constrained and appropriately normed meta-GGA achieves remarkable accuracy for systems where the exact exchange-correlation hole is localized near its electron, and especially for lattice constants and weak interactions. [ABSTRACT FROM AUTHOR]

We demonstrate that the charge-spin conversion efficiency of topological insulators (TI) can be experimentally determined by injecting spin-polarized tunneling electrons into a TI. Through a comparative study between bismuth selenide and bismuth antimony telluride, we verified the topological-surface-state origin of the observed giant spin signals. By injecting energetic electrons into bismuth selenide, we further studied the energy dependence of the effective spin polarization at the TI surface. The experimentally verified large spin polarization, as well as our calculations, provides new insights into optimizing TI materials for near room-temperature spintronic applications. [ABSTRACT FROM AUTHOR]

A remarkably large spin signal is observed on nonmagnetic W(110) for a highly symmetric unoccupied state with no intrinsic spin polarization. The magnitude and, more importantly, the sign of this spin signal, measured by spin- and angle-resolved inverse photoemission for normal electron incidence, can be tuned in a user-defined manner by variation of the photon-detection angle and/or by rotating the spin-polarization direction of the incident electrons. Using calculations of the orbitally decomposed spectral densities, this effect is traced back to a mixing of different symmetries within the respective state. This explanation is underlined by the behavior of a second electronic state of pure symmetry, which does not show such a spin signal. In general, the spin signals of electronic states are not only influenced by their intrinsic spin polarization but also by the choice of symmetry-breaking experimental parameters in combination with the particular orbital characters of the states under investigation. The latter permits one to tune the spin signal in magnitude and sign. [ABSTRACT FROM AUTHOR]

We introduce a distinct approach to engineer a topologically protected surface state of a topological insulator. By covering the surface of a topological insulator, Bi2Te2Se, with a Bi monolayer film, the original surface state is completely removed and three new spin helical surface states, originating from the Bi film, emerge with different dispersion and spin polarization, through a strong electron hybridization. These new states play the role of topological surface states keeping the bulk topological nature intact. This mechanism provides a way to create various different types of topologically protected electron channels on top of a single topological insulator, possibly with tailored properties for various applications. [ABSTRACT FROM AUTHOR]

The spin orientation of electrons is studied in ferromagnet (FM)-semiconductor (SC) hybrid structures composed of a (Ga,Mn)As ferromagnetic layer, which is placed in the direct vicinity of a non-magnetic SC [ABSTRACT FROM AUTHOR]