Photocatalytic and photoelectrochemical water splitting using semiconductor materials are effective approaches for converting solar energy into hydrogen fuel.In the past few years,a series of photocatalysts/photoelect...Photocatalytic and photoelectrochemical water splitting using semiconductor materials are effective approaches for converting solar energy into hydrogen fuel.In the past few years,a series of photocatalysts/photoelectrocatalysts have been developed and optimized to achieve efficient solar hydrogen production.Among various optimization strategies,the regulation of spin polarization can tailor the intrinsic optoelectronic properties for retarding charge recombination and enhancing surface reactions,thus improving the solar-to-hydrogen(STH)efficiency.This review presents recent advances in the regulation of spin polarization to enhance spin polarized-dependent solar hydrogen evolution activity.Specifically,spin polarization manipulation strategies of several typical photocatalysts/photoelectrocatalysts(e.g.,metallic oxides,metallic sulfides,non-metallic semiconductors,ferroelectric materials,and chiral molecules)are described.In the end,the critical challenges and perspectives of spin polarization regulation towards future solar energy conversion are briefly provided.展开更多
Rashba spin splitting(RSS)and quantum spin Hall effect(QSHE)have attracted enormous interest due to their great significance in the application of spintronics.In this work,we theoretically proposed a new two-dimension...Rashba spin splitting(RSS)and quantum spin Hall effect(QSHE)have attracted enormous interest due to their great significance in the application of spintronics.In this work,we theoretically proposed a new two-dimensional(2D)material H–Pb–F with coexistence of giant RSS and quantum spin Hall effec by using the ab initio calculations.Our results show that H–Pb–F possesses giant RSS(1.21 eV·A)and the RSS can be tuned up to 4.16 e V·A by in-plane biaxial strain,which is a huge value among 2D materials.Furthermore,we also noticed that H–Pb–F is a 2D topological insulator(TI)duo to the strong spin–orbit coupling(SOC)interaction,and the large topological gap is up to 1.35 e V,which is large enough for for the observation of topological edge states at room temperature.The coexistence of giant RSS and quantum spin Hall effect greatly broadens the potential application of H–Pb–F in the field of spintronic devices.展开更多
We have studied the characteristics of current-induced nonequilibrium spin polarization in semiconductor-nanowire/swave superconductor junctions with strong spin–orbit coupling. It was found that within some paramete...We have studied the characteristics of current-induced nonequilibrium spin polarization in semiconductor-nanowire/swave superconductor junctions with strong spin–orbit coupling. It was found that within some parameter regions the magnitude of the current-induced nonequilibrium spin polarization density in such structures will increase(or decrease) with the decrease(or increase) of the charge current density, in contrast to that found in normal spin–orbit coupled semiconductor structures. It was also found that the unusual characteristics of the current-induced nonequilibrium spin polarization in such structures can be well explained by the effect of the Andreev reflection.展开更多
We report a theoretic study on modulating the spin polarization of charge current in a mesoscopic four-terminaldevice of cross structure by using the inverse spin hall effect.The scattering region of device is a two-d...We report a theoretic study on modulating the spin polarization of charge current in a mesoscopic four-terminaldevice of cross structure by using the inverse spin hall effect.The scattering region of device is a two-dimensionalelectron gas(2DEG)with Rashba spin orbital interaction(RSOI),one of lead is ferromagnetic metal and other threeleads are spin-degenerate normal metals.By using Landauer-Büttiker formalism,we found that when a longitudinalcharge current Rows through 2DEG scattering region from FM lead by external bias,the transverse current can be eithera pure spin current or full-polarized charge current due to the combined effect of spin hall effect and its inverse process,and the polarization of this transverse current can be easily controlled by several device parameters such as the Fermienergy,ferromagnetic magnetization,and the RSOI constant.Our method may pave a new way to control the spinpolarization of a charge current.展开更多
Electrocatalytic water splitting is limited by kinetics-sluggish oxygen evolution,in which the activity of catalysts depends on their electronic structure.However,the infl uence of electron spin polarization on cataly...Electrocatalytic water splitting is limited by kinetics-sluggish oxygen evolution,in which the activity of catalysts depends on their electronic structure.However,the infl uence of electron spin polarization on catalytic activity is ambiguous.Herein,we successfully regulate the spin polarization of Co_(3)O_(4)catalysts by tuning the concentration of cobalt defects from 0.8 to 14.5%.X-ray absorption spectroscopy spectra and density functional theory calculations confi rm that the spin polarization of Co_(3)O_(4)is positively correlated with the concentration of cobalt defects.Importantly,the enhanced spin polarization can increase hydroxyl group absorption to signifi cantly decrease the Gibbs free energy change value of the OER rate-determining step and regulate the spin polarization of oxygen species through a spin electron-exchange process to easily produce triplet-state O_(2),which can obviously increase electrocatalytic OER activity.In specifi c,Co_(3)O_(4)-50 with 14.5%cobalt defects exhibits the highest spin polarization and shows the best normalized OER activity.This work provides an important strategy to increase the water splitting activity of electrocatalysts via the rational regulation of electron spin polarization.展开更多
The spin dependent electron transmission phenomenon in a diluted resonant semiconductor heterostructure is employed theoretically to investigate the output transmission current polarization at zero magnetic field. Tra...The spin dependent electron transmission phenomenon in a diluted resonant semiconductor heterostructure is employed theoretically to investigate the output transmission current polarization at zero magnetic field. Transparency of electron transmission is calculated as a function of electron energy and the well width, within the one electron band approximation along with the spin orbit interaction. Enhanced spin-polarized resonant tunneling in the heterostructure due to Dresselhaus and Rashba spin-orbit coupling induced splitting of the resonant level is observed. We predict that a spin-polarized current spontaneously emerges in this heterostructure and we estimate theoretically that the polarization can reach 40%. This effect could be employed in the fabrication of spin filters, spin injectors and detectors based on non-magnetic semiconductors.展开更多
Polymers are usually restricted on the high exciton binding energies and sluggish electron transfer because of the low dielectric constants.Regulating spin-polarized electrons is regarded as an attractive strategy,but...Polymers are usually restricted on the high exciton binding energies and sluggish electron transfer because of the low dielectric constants.Regulating spin-polarized electrons is regarded as an attractive strategy,but often confined to the d-orbital elements.Here,the nonmetal P and N elements co-mediated the spin polarization of carbon nitrides(PCN)have been elaborately designed.The optimized PCN-3 shows an outstanding hydrogen production(22.2 mmol·g^(-1)·h^(-1))coupled with selective benzylamine oxidation without using any solvent and cocatalysts,which is 200 times of original C_(3)N_(4)and superior to the photocatalysts has been reported to date.Experimental and theoretical results verified that the spin-orbital coupling of N 2p and P 2p remarkably increased the parallel spin states of charge and reduced the formation of singlet excitons to accelerate exciton dissociation in carbon nitride.In addition,charge separation and surface catalysis can be significantly enhanced by the electron spin polarization of carbon nitride with the parallel arrangement,huge built-in electric field and disturbed electronic structure.Our finding deepens the insight into the charge separation and exciton dissociation in spin polarization,and offers new tactics to develop high-efficiency catalysts.展开更多
The spin polarization phenomenon in lepton circular accelerators had been known for many years. It provides a new approach for physicists to study the spin feature of fundamental particles and the dynamics of spin-orb...The spin polarization phenomenon in lepton circular accelerators had been known for many years. It provides a new approach for physicists to study the spin feature of fundamental particles and the dynamics of spin-orbit coupling, such as spin resonances. We use numerical simulation to study the features of spin under the modulation of orbital motion in an electron storage ring. The various cases of depolarization due to spin-orbit coupling through an emitting photon and misalignment of magnets in the ring are discussed.展开更多
We develop a model Hamiltonian to treat anomalous Hall conductivity in dilute magnetic semiconductor (DMS) of type (III, Mn, V) considering the impurity potentials (potential due to interaction of spin of carriers wit...We develop a model Hamiltonian to treat anomalous Hall conductivity in dilute magnetic semiconductor (DMS) of type (III, Mn, V) considering the impurity potentials (potential due to interaction of spin of carriers with localized spin of dopant (Mn) and coulomb like potential). Using equation of motion in Green function together with Quantum Kubo-formula of conductivity, the anomalous Hall conductivity is calculated as function of spin-orbit coupling, exchange field and carrier polarization. The calculated result shows that at low impurity concentration, the interplay between spin polarization of carriers, spin-orbit coupling and exchange fields is crucial for existence of anomalous Hall conductivity. The monotonic increment of anomalous Hall conductivity with exchange field is observed for strong spin-orbit coupling limit. In weak spin-orbit coupling limit, the magnitude of anomalous Hall conductivity increases parabolically with the spin-orbit coupling. Our results provide an important basis for understanding the interplay between the spin polarization, spin-orbit coupling, and exchange field on anomalous Hall conductivity at low impurity concentration. The findings are also a key step to realize dissipationless quantum transport without external magnetic field.展开更多
The Rashba coefficient and Rashba spin splitting for the first subband of the Alo.5Gao.5N/GaN/ Alo.5Gao.5N quantum well (QW) with various sheet carrier densities (Ns) are calculated by solving Schr6dinger and Pois...The Rashba coefficient and Rashba spin splitting for the first subband of the Alo.5Gao.5N/GaN/ Alo.5Gao.5N quantum well (QW) with various sheet carrier densities (Ns) are calculated by solving Schr6dinger and Poisson equations self-consistently. The Rashba spin splitting for the first subband at the Fermi level is considerable and increases evidently with Ns, since the Rashba coefficient, especially the Fermi wave vector increase rapidly. With increasing Ns, the peak of the wave function for the first subband moves towards the left heterointerface, and the average electric field in the well increases, so the two dominant contributions coming from the well and the heterointerface increase. Therefore, the strong polarization electric field and high density of 2DEG in III-nitrides heterostructures are of great importance to a and make the Rashba spin splitting in A1GaN/GaN QWs comparable to that of narrow-gap III-V materials. The results indicate that the sheet carrier density is an important parameter affecting the Rashba coefficient and Rashba spin splitting in A1GaN/GaN QWs, showing the possible application of this material system in spintronic devices.展开更多
Hidden spin polarization refers to that doubly degenerate bands protected by combined inversion and time-reversal symmetry in nonmagnetic inversion-symmetric crystals could have opposite non-zero local spin polarizati...Hidden spin polarization refers to that doubly degenerate bands protected by combined inversion and time-reversal symmetry in nonmagnetic inversion-symmetric crystals could have opposite non-zero local spin polarizations, which are spatially separated in two real-space sectors paired by the inversion symmetry. Since its first prediction from ab initio calculation, hidden spin polarization has inspired tremendous interest and has been observed experimentally due to its intriguing fundamental properties as well as the great potential for applications. Moving forward, the search for moment-dependent spin splitting has also been extended to antiferromagnets even without considering spin-orbit coupling. This paper systematically reviews recent works in this field with a focus on basic concepts and material realization. It also details several remaining bottlenecks and suggests possible avenues for future research.展开更多
Motivated by the recent discovery of a strongly spin-orbit-coupled two-dimensional (2D) electron gas near the surface of Rashba semiconductors BiTeX (X = Cl, Br, I), we calculate the thermoelectric responses of sp...Motivated by the recent discovery of a strongly spin-orbit-coupled two-dimensional (2D) electron gas near the surface of Rashba semiconductors BiTeX (X = Cl, Br, I), we calculate the thermoelectric responses of spin polarization in a 2D Rashba model. By self-consistently determining the energy- and band-dependent transport time, we present tion for elastic scattering. Using this solution, an exact solution of the linearized Boltzmann equa- we find a non-Edelstein electric-field-induced spin polarization that is linear in the Fermi energy EF when EF lies below the band crossing point. The spin polarization efficiency, which is the electric-field-induced spin polarization divided by the driven electric current, increases for smaller EF. We show that, as a function of EF, the temperature- gradient-induced spin polarization increases continuously to a saturation value when EF decreases below the band crossing point. As the temperature tends to zero, the temperature-gradient-induced spin polarization vanishes.展开更多
The influence of electron-phonon (EP) scattering on spin polarization of current output from a mesoscopic ring with Rashba spin-orbit (SO) interaction is numerically investigated. There are three leads connecting ...The influence of electron-phonon (EP) scattering on spin polarization of current output from a mesoscopic ring with Rashba spin-orbit (SO) interaction is numerically investigated. There are three leads connecting to the ring at different positionsl unpolarized current is injected to one of them, and the other two are output channels with different bias voltages. The spin polarization of current in the outgoing leads shows oscillations as a function of EP coupling strength owing to the quantum interference of EP states in the ring region. As temperature increases, the oscillations are evidently suppressed, implying decoherence of the EP states. The simulation shows that the magnitude of polarized current is sensitive to the location of the lead. The polarized current depends on the connecting position of the lead in a complicated way due to the spin-sensitive quantum interference effects caused by different phases accumulated by transmitting electrons with opposite spin states along different paths.展开更多
We investigate theoretically the spin-dependent electron transport in a straight waveguide with Rashba spin-orbit coupling (SOC) under the irradiation of a transversely polarized electromagnetic (EM) field. Spin-d...We investigate theoretically the spin-dependent electron transport in a straight waveguide with Rashba spin-orbit coupling (SOC) under the irradiation of a transversely polarized electromagnetic (EM) field. Spin-dependent electron conductance and spin polarization are calculated as functions of the emitting energy of electrons or the strength of the EM field by adopting the mode matching approach. It is shown that the spin polarization can be manipulated by external parameters when the strength of Rashba SOC is strong. Furthermore, a sharp step structure is found to exist in the total electron conductance. These results can he understood by the nontrivial Rashba subbands intermixing and the electron intersubband transition when a finite-range transversely polarized EM field irradiates a straight waveguide.展开更多
Influence of spin–orbit coupling on spin-polarized electronic transport in magnetic semiconductor nanowires with nanosized sharp domain walls is investigated theoretically.It is shown that the Rashba spin–orbit coup...Influence of spin–orbit coupling on spin-polarized electronic transport in magnetic semiconductor nanowires with nanosized sharp domain walls is investigated theoretically.It is shown that the Rashba spin–orbit coupling can enhance significantly the spin-flip scattering of charge carriers from a nanosized sharp domain wall whose extension is much smaller than the carrier's Fermi wavelength.When there are more than one domain wall presented in a magnetic semiconductor nanowire,not only the spin-flip scattering of charge carriers from the domain walls but the quantum interference of charge carriers in the intermediate domain regions between neighboring domain walls may play important roles on spin-polarized electronic transport,and in such cases the influences of the Rashba spin–orbit coupling will depend sensitively both on the domain walls' width and the domain walls' separation.展开更多
We study the properties of superfluid in a two-dimensional (2D) polarized Fermi gas with spin-orbit coupling and adiabatic rotation which are trapped in a harmonic potential. Due to the competition between polarizat...We study the properties of superfluid in a two-dimensional (2D) polarized Fermi gas with spin-orbit coupling and adiabatic rotation which are trapped in a harmonic potential. Due to the competition between polarization, spin-orbit coupling, and adiabatic rotation, the Fermi gas exhibits many intriguing phenomena. By using the Bardeen-Cooper-Schrieffer (BCS) mean-field method with local density approximation, we investigate the dependence of order parameter solution on the spin-orbit coupling strength and the rotation velocity. The energy spectra with different rotation velocities are studied in detail. Besides, the conditions for the zero-energy Majorana fermions in topological superfluid phase to be observed are obtained. By investigating distributions of number density, we find that the rotation has opposite effect on the distribution of number density with different spins, which leads to the enhancement of the polarization of Fermi gas. Here, we focus on the region of BCS pairing and ignore the Fulde-Ferrell-Larkin-Ovchinnikov state.展开更多
We theoretically investigate the spin-orbit interaction in GaAs/AlxGal_xAs coupled quantum wells. We consider the contribution of the interface-related Rashba term as well as the linear and cubic Dresselhaus terms to ...We theoretically investigate the spin-orbit interaction in GaAs/AlxGal_xAs coupled quantum wells. We consider the contribution of the interface-related Rashba term as well as the linear and cubic Dresselhaus terms to the spin splitting. For the coupled quantum wells which bear an inherent structure inversion asymmetry, the same probability density distribution of electrons in the two step quantum wells results in a large spin splitting from the interface term. If the widths of the two step quantum wells are different, the electron probability density in the wider step quantum well is considerably higher than that in the narrower one, resulting in the decrease of the spin splitting from the interface term. The results also show that the spin splitting of the coupled quantum well is not significantly larger than that of a step quantum well.展开更多
In this study, we investigate theoretically the effect of spin-orbit coupling on the energy level spectrum and spin texturing of a quantum wire with a parabolic confining potential subjected to the perpendicular magne...In this study, we investigate theoretically the effect of spin-orbit coupling on the energy level spectrum and spin texturing of a quantum wire with a parabolic confining potential subjected to the perpendicular magnetic field. Highly accurate numerical calculations have been carried out using a finite element method. Our results reveal that the interplay between the spin-orbit interaction and the effective magnetic field significantly modifies the band structure, producing additional subband extrema and energy gaps. Competing effects between external field and spin-orbit interactions introduce comp|ex features in spin texturing owing to the couplings in energy subbands. We obtain that spatia~ modulation of the spin density along the wire width can be considerably modified by the spin-orbit coupling strength, magnetic field and charge carrier concentration.展开更多
We used density functional calculations to investigate the electronic origins of the magnetic properties of the high-spin ferric enzyme-substrate complex protocatechuate 3,4-dioxygenase(3,4-PCD).The calculated g-tenso...We used density functional calculations to investigate the electronic origins of the magnetic properties of the high-spin ferric enzyme-substrate complex protocatechuate 3,4-dioxygenase(3,4-PCD).The calculated g-tensors show that ligand-to-metal charge transfer transitions are from the protocatechuate(PCA) and Tyr408 orbitals to the Fe d orbitals,which lead to x-and y-polarized transitions.These polarized transitions require a spin-orbit coupling(SOC) matrix element in the z-direction,Lz(z=z'),resulting in a g z value of 2.0158,significantly deviating from 2.0023.A large zero-field splitting parameter value of+1.147cm-1 is due to △S =-1 spin-orbit mixing with the quartet states for the sextet ground state,accounting for around 73% of the SOC contribution.The SOC matrix elements indicate that the high-spin d 5 system Fe(Ⅲ),3,4-PCD-PCA is a weak spin-crossover compound with an SOC of 31.56 cm-1.展开更多
基金support from the National Natural Science Foundation of China(No.22105031)National Key Research and Development Program of China(No.2019YFE0121600)+2 种基金Sichuan Science and Technology Program(No.2021YFH0054,2023JDGD0011)Fundamental Research Funds for the Central Universities(ZYGX2020J028)Z.M.W.acknowledges the National Key Research and Development Program of China(No.2019YFB2203400)and the“111 Project”(No.B20030).
文摘Photocatalytic and photoelectrochemical water splitting using semiconductor materials are effective approaches for converting solar energy into hydrogen fuel.In the past few years,a series of photocatalysts/photoelectrocatalysts have been developed and optimized to achieve efficient solar hydrogen production.Among various optimization strategies,the regulation of spin polarization can tailor the intrinsic optoelectronic properties for retarding charge recombination and enhancing surface reactions,thus improving the solar-to-hydrogen(STH)efficiency.This review presents recent advances in the regulation of spin polarization to enhance spin polarized-dependent solar hydrogen evolution activity.Specifically,spin polarization manipulation strategies of several typical photocatalysts/photoelectrocatalysts(e.g.,metallic oxides,metallic sulfides,non-metallic semiconductors,ferroelectric materials,and chiral molecules)are described.In the end,the critical challenges and perspectives of spin polarization regulation towards future solar energy conversion are briefly provided.
基金the National Natural Science Foundation of China(Grant Nos.11874316,11404275,and 11474244)the National Basic Research Program of China(Grant No.2015CB921103)+2 种基金the Natural Science Foundation of Hunan Province,China(Grant Nos.2016JJ3118 and 2020JJ4244)the Scientific Research Foundation of the Education Bureau of Hunan Province,China(Grant Nos.16K084,17K086,and 21A049)the Fund for the Innovative Research Team in University(Grant No.IRT13093).
文摘Rashba spin splitting(RSS)and quantum spin Hall effect(QSHE)have attracted enormous interest due to their great significance in the application of spintronics.In this work,we theoretically proposed a new two-dimensional(2D)material H–Pb–F with coexistence of giant RSS and quantum spin Hall effec by using the ab initio calculations.Our results show that H–Pb–F possesses giant RSS(1.21 eV·A)and the RSS can be tuned up to 4.16 e V·A by in-plane biaxial strain,which is a huge value among 2D materials.Furthermore,we also noticed that H–Pb–F is a 2D topological insulator(TI)duo to the strong spin–orbit coupling(SOC)interaction,and the large topological gap is up to 1.35 e V,which is large enough for for the observation of topological edge states at room temperature.The coexistence of giant RSS and quantum spin Hall effect greatly broadens the potential application of H–Pb–F in the field of spintronic devices.
基金Project supported by the National Natural Science Foundation of China(Grant No.11474106)
文摘We have studied the characteristics of current-induced nonequilibrium spin polarization in semiconductor-nanowire/swave superconductor junctions with strong spin–orbit coupling. It was found that within some parameter regions the magnitude of the current-induced nonequilibrium spin polarization density in such structures will increase(or decrease) with the decrease(or increase) of the charge current density, in contrast to that found in normal spin–orbit coupled semiconductor structures. It was also found that the unusual characteristics of the current-induced nonequilibrium spin polarization in such structures can be well explained by the effect of the Andreev reflection.
基金Supported by National Natural Science Foundation of China under Grant No.10704016Natural Science Foundation of Jiangsu Province under Grant Nos.BK2007100Ministry of Education of China under Grant No.MEC-20070286036
文摘We report a theoretic study on modulating the spin polarization of charge current in a mesoscopic four-terminaldevice of cross structure by using the inverse spin hall effect.The scattering region of device is a two-dimensionalelectron gas(2DEG)with Rashba spin orbital interaction(RSOI),one of lead is ferromagnetic metal and other threeleads are spin-degenerate normal metals.By using Landauer-Büttiker formalism,we found that when a longitudinalcharge current Rows through 2DEG scattering region from FM lead by external bias,the transverse current can be eithera pure spin current or full-polarized charge current due to the combined effect of spin hall effect and its inverse process,and the polarization of this transverse current can be easily controlled by several device parameters such as the Fermienergy,ferromagnetic magnetization,and the RSOI constant.Our method may pave a new way to control the spinpolarization of a charge current.
基金The authors appreciate the fi nancial support from the National Natural Science Foundation of China(Nos.21978200 and 22161142002)the Haihe Laboratory of Sustainable Chemical Transformations(CYZC202103).
文摘Electrocatalytic water splitting is limited by kinetics-sluggish oxygen evolution,in which the activity of catalysts depends on their electronic structure.However,the infl uence of electron spin polarization on catalytic activity is ambiguous.Herein,we successfully regulate the spin polarization of Co_(3)O_(4)catalysts by tuning the concentration of cobalt defects from 0.8 to 14.5%.X-ray absorption spectroscopy spectra and density functional theory calculations confi rm that the spin polarization of Co_(3)O_(4)is positively correlated with the concentration of cobalt defects.Importantly,the enhanced spin polarization can increase hydroxyl group absorption to signifi cantly decrease the Gibbs free energy change value of the OER rate-determining step and regulate the spin polarization of oxygen species through a spin electron-exchange process to easily produce triplet-state O_(2),which can obviously increase electrocatalytic OER activity.In specifi c,Co_(3)O_(4)-50 with 14.5%cobalt defects exhibits the highest spin polarization and shows the best normalized OER activity.This work provides an important strategy to increase the water splitting activity of electrocatalysts via the rational regulation of electron spin polarization.
文摘The spin dependent electron transmission phenomenon in a diluted resonant semiconductor heterostructure is employed theoretically to investigate the output transmission current polarization at zero magnetic field. Transparency of electron transmission is calculated as a function of electron energy and the well width, within the one electron band approximation along with the spin orbit interaction. Enhanced spin-polarized resonant tunneling in the heterostructure due to Dresselhaus and Rashba spin-orbit coupling induced splitting of the resonant level is observed. We predict that a spin-polarized current spontaneously emerges in this heterostructure and we estimate theoretically that the polarization can reach 40%. This effect could be employed in the fabrication of spin filters, spin injectors and detectors based on non-magnetic semiconductors.
基金financially supported by Guizhou Provincial Science and Technology Foundation(No.ZK2021069)Young Science and Technology Talents Development Project of Education Department in Guizhou Province(No.KY2022144)National Natural Science Foundation of China(No.22268015).
文摘Polymers are usually restricted on the high exciton binding energies and sluggish electron transfer because of the low dielectric constants.Regulating spin-polarized electrons is regarded as an attractive strategy,but often confined to the d-orbital elements.Here,the nonmetal P and N elements co-mediated the spin polarization of carbon nitrides(PCN)have been elaborately designed.The optimized PCN-3 shows an outstanding hydrogen production(22.2 mmol·g^(-1)·h^(-1))coupled with selective benzylamine oxidation without using any solvent and cocatalysts,which is 200 times of original C_(3)N_(4)and superior to the photocatalysts has been reported to date.Experimental and theoretical results verified that the spin-orbital coupling of N 2p and P 2p remarkably increased the parallel spin states of charge and reduced the formation of singlet excitons to accelerate exciton dissociation in carbon nitride.In addition,charge separation and surface catalysis can be significantly enhanced by the electron spin polarization of carbon nitride with the parallel arrangement,huge built-in electric field and disturbed electronic structure.Our finding deepens the insight into the charge separation and exciton dissociation in spin polarization,and offers new tactics to develop high-efficiency catalysts.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10875118)
文摘The spin polarization phenomenon in lepton circular accelerators had been known for many years. It provides a new approach for physicists to study the spin feature of fundamental particles and the dynamics of spin-orbit coupling, such as spin resonances. We use numerical simulation to study the features of spin under the modulation of orbital motion in an electron storage ring. The various cases of depolarization due to spin-orbit coupling through an emitting photon and misalignment of magnets in the ring are discussed.
文摘We develop a model Hamiltonian to treat anomalous Hall conductivity in dilute magnetic semiconductor (DMS) of type (III, Mn, V) considering the impurity potentials (potential due to interaction of spin of carriers with localized spin of dopant (Mn) and coulomb like potential). Using equation of motion in Green function together with Quantum Kubo-formula of conductivity, the anomalous Hall conductivity is calculated as function of spin-orbit coupling, exchange field and carrier polarization. The calculated result shows that at low impurity concentration, the interplay between spin polarization of carriers, spin-orbit coupling and exchange fields is crucial for existence of anomalous Hall conductivity. The monotonic increment of anomalous Hall conductivity with exchange field is observed for strong spin-orbit coupling limit. In weak spin-orbit coupling limit, the magnitude of anomalous Hall conductivity increases parabolically with the spin-orbit coupling. Our results provide an important basis for understanding the interplay between the spin polarization, spin-orbit coupling, and exchange field on anomalous Hall conductivity at low impurity concentration. The findings are also a key step to realize dissipationless quantum transport without external magnetic field.
基金Project supported by the National Natural Science Foundation of China(Nos.61306012,11004168)the Program for Science & Technology Innovation Talents in Universities of Henan Province(No.2012HASTIT033)
文摘The Rashba coefficient and Rashba spin splitting for the first subband of the Alo.5Gao.5N/GaN/ Alo.5Gao.5N quantum well (QW) with various sheet carrier densities (Ns) are calculated by solving Schr6dinger and Poisson equations self-consistently. The Rashba spin splitting for the first subband at the Fermi level is considerable and increases evidently with Ns, since the Rashba coefficient, especially the Fermi wave vector increase rapidly. With increasing Ns, the peak of the wave function for the first subband moves towards the left heterointerface, and the average electric field in the well increases, so the two dominant contributions coming from the well and the heterointerface increase. Therefore, the strong polarization electric field and high density of 2DEG in III-nitrides heterostructures are of great importance to a and make the Rashba spin splitting in A1GaN/GaN QWs comparable to that of narrow-gap III-V materials. The results indicate that the sheet carrier density is an important parameter affecting the Rashba coefficient and Rashba spin splitting in A1GaN/GaN QWs, showing the possible application of this material system in spintronic devices.
基金supported by the National Science Fund for Distinguished Young Scholars(Grant No.11925407)the National Natural Science Foundation of China(Grant No.11904359)+2 种基金the Basic Science Center Program of the National Natural Science Foundation of China(Grant No.61888102)the Key Research Program of Frontier Sciences,CAS(Grant No.ZDBSLY-JSC019)the National Key Research and Development Program of China(Grant No.2018YFB2202800)。
文摘Hidden spin polarization refers to that doubly degenerate bands protected by combined inversion and time-reversal symmetry in nonmagnetic inversion-symmetric crystals could have opposite non-zero local spin polarizations, which are spatially separated in two real-space sectors paired by the inversion symmetry. Since its first prediction from ab initio calculation, hidden spin polarization has inspired tremendous interest and has been observed experimentally due to its intriguing fundamental properties as well as the great potential for applications. Moving forward, the search for moment-dependent spin splitting has also been extended to antiferromagnets even without considering spin-orbit coupling. This paper systematically reviews recent works in this field with a focus on basic concepts and material realization. It also details several remaining bottlenecks and suggests possible avenues for future research.
文摘Motivated by the recent discovery of a strongly spin-orbit-coupled two-dimensional (2D) electron gas near the surface of Rashba semiconductors BiTeX (X = Cl, Br, I), we calculate the thermoelectric responses of spin polarization in a 2D Rashba model. By self-consistently determining the energy- and band-dependent transport time, we present tion for elastic scattering. Using this solution, an exact solution of the linearized Boltzmann equa- we find a non-Edelstein electric-field-induced spin polarization that is linear in the Fermi energy EF when EF lies below the band crossing point. The spin polarization efficiency, which is the electric-field-induced spin polarization divided by the driven electric current, increases for smaller EF. We show that, as a function of EF, the temperature- gradient-induced spin polarization increases continuously to a saturation value when EF decreases below the band crossing point. As the temperature tends to zero, the temperature-gradient-induced spin polarization vanishes.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10474033 and 60676056)the State Key Projects of Basic Research of China (Grant Nos 2006CB0L1000 and 2005CB623605)
文摘The influence of electron-phonon (EP) scattering on spin polarization of current output from a mesoscopic ring with Rashba spin-orbit (SO) interaction is numerically investigated. There are three leads connecting to the ring at different positionsl unpolarized current is injected to one of them, and the other two are output channels with different bias voltages. The spin polarization of current in the outgoing leads shows oscillations as a function of EP coupling strength owing to the quantum interference of EP states in the ring region. As temperature increases, the oscillations are evidently suppressed, implying decoherence of the EP states. The simulation shows that the magnitude of polarized current is sensitive to the location of the lead. The polarized current depends on the connecting position of the lead in a complicated way due to the spin-sensitive quantum interference effects caused by different phases accumulated by transmitting electrons with opposite spin states along different paths.
基金Project supported by the National Natural Science Foundation of China (Grant No 10774112)by the Science Foundation for Young Scientists of Jiangxi Agricultural University,China (Grant No 2219)
文摘We investigate theoretically the spin-dependent electron transport in a straight waveguide with Rashba spin-orbit coupling (SOC) under the irradiation of a transversely polarized electromagnetic (EM) field. Spin-dependent electron conductance and spin polarization are calculated as functions of the emitting energy of electrons or the strength of the EM field by adopting the mode matching approach. It is shown that the spin polarization can be manipulated by external parameters when the strength of Rashba SOC is strong. Furthermore, a sharp step structure is found to exist in the total electron conductance. These results can he understood by the nontrivial Rashba subbands intermixing and the electron intersubband transition when a finite-range transversely polarized EM field irradiates a straight waveguide.
文摘Influence of spin–orbit coupling on spin-polarized electronic transport in magnetic semiconductor nanowires with nanosized sharp domain walls is investigated theoretically.It is shown that the Rashba spin–orbit coupling can enhance significantly the spin-flip scattering of charge carriers from a nanosized sharp domain wall whose extension is much smaller than the carrier's Fermi wavelength.When there are more than one domain wall presented in a magnetic semiconductor nanowire,not only the spin-flip scattering of charge carriers from the domain walls but the quantum interference of charge carriers in the intermediate domain regions between neighboring domain walls may play important roles on spin-polarized electronic transport,and in such cases the influences of the Rashba spin–orbit coupling will depend sensitively both on the domain walls' width and the domain walls' separation.
文摘We study the properties of superfluid in a two-dimensional (2D) polarized Fermi gas with spin-orbit coupling and adiabatic rotation which are trapped in a harmonic potential. Due to the competition between polarization, spin-orbit coupling, and adiabatic rotation, the Fermi gas exhibits many intriguing phenomena. By using the Bardeen-Cooper-Schrieffer (BCS) mean-field method with local density approximation, we investigate the dependence of order parameter solution on the spin-orbit coupling strength and the rotation velocity. The energy spectra with different rotation velocities are studied in detail. Besides, the conditions for the zero-energy Majorana fermions in topological superfluid phase to be observed are obtained. By investigating distributions of number density, we find that the rotation has opposite effect on the distribution of number density with different spins, which leads to the enhancement of the polarization of Fermi gas. Here, we focus on the region of BCS pairing and ignore the Fulde-Ferrell-Larkin-Ovchinnikov state.
基金Project supported by the National Natural Science Foundation of China (Grant No. 61204107)the Scientific Research Fund of Zhejiang Provincial Education Department, China (Grant No. Y201120799)
文摘We theoretically investigate the spin-orbit interaction in GaAs/AlxGal_xAs coupled quantum wells. We consider the contribution of the interface-related Rashba term as well as the linear and cubic Dresselhaus terms to the spin splitting. For the coupled quantum wells which bear an inherent structure inversion asymmetry, the same probability density distribution of electrons in the two step quantum wells results in a large spin splitting from the interface term. If the widths of the two step quantum wells are different, the electron probability density in the wider step quantum well is considerably higher than that in the narrower one, resulting in the decrease of the spin splitting from the interface term. The results also show that the spin splitting of the coupled quantum well is not significantly larger than that of a step quantum well.
基金Project supported by Research Grants DEU-BAP:2009183 and DEU-BAP:2009184 from Scientific Research Fund of Dokuz EyliJl University.
文摘In this study, we investigate theoretically the effect of spin-orbit coupling on the energy level spectrum and spin texturing of a quantum wire with a parabolic confining potential subjected to the perpendicular magnetic field. Highly accurate numerical calculations have been carried out using a finite element method. Our results reveal that the interplay between the spin-orbit interaction and the effective magnetic field significantly modifies the band structure, producing additional subband extrema and energy gaps. Competing effects between external field and spin-orbit interactions introduce comp|ex features in spin texturing owing to the couplings in energy subbands. We obtain that spatia~ modulation of the spin density along the wire width can be considerably modified by the spin-orbit coupling strength, magnetic field and charge carrier concentration.
基金Supported by National Natural Science Foundation of China under Grant Nos.110704032 and 110704033the Natural Science Foundation of JiangSu Province under Grant No.BK2010416
基金supported by the "QingLan" Talent Engineering Fundsthrough Tian Shui Normal Universitythe Key Project of the Chinese Ministry of Education (211189)
文摘We used density functional calculations to investigate the electronic origins of the magnetic properties of the high-spin ferric enzyme-substrate complex protocatechuate 3,4-dioxygenase(3,4-PCD).The calculated g-tensors show that ligand-to-metal charge transfer transitions are from the protocatechuate(PCA) and Tyr408 orbitals to the Fe d orbitals,which lead to x-and y-polarized transitions.These polarized transitions require a spin-orbit coupling(SOC) matrix element in the z-direction,Lz(z=z'),resulting in a g z value of 2.0158,significantly deviating from 2.0023.A large zero-field splitting parameter value of+1.147cm-1 is due to △S =-1 spin-orbit mixing with the quartet states for the sextet ground state,accounting for around 73% of the SOC contribution.The SOC matrix elements indicate that the high-spin d 5 system Fe(Ⅲ),3,4-PCD-PCA is a weak spin-crossover compound with an SOC of 31.56 cm-1.