Moleculardeviceswith highswitchingperformance and/or the perfect spin filtering effect have always been the pursuit with the development of molecular electronics.Hereb,yusingthe 2001.0V nonequilibrium.Green's func...Moleculardeviceswith highswitchingperformance and/or the perfect spin filtering effect have always been the pursuit with the development of molecular electronics.Hereb,yusingthe 2001.0V nonequilibrium.Green's function method in combination with the density functionaltheory,the switching performance and spin filtering properties of dimethyldihydropyrene(DHP)/cyclophanediene(CPD)photoswitchable molecule connected by carbon atomic chains(CACs)to two zigzag graphene nanoribbon electrodes have been theoretically investigated.The results show that DHP is more conductive than CPD and therefore an evident switching effect is demonstrated,and the switching ratio(RON/OFF)can reach 4.5×103.It is further revealed that the RoON/OF of DHP/CPD closely depends on the length of CACs.More specifically,the RoN/OFF values of DHP/CPD with odd-numbered CACs are larger than those with even-numbered CACs.More interestingly,a high or even perfect spin filtering effect can be obtained in these investigated DHP/CPD single-molecule devices.Our study is helpful for future design of single-molecule switches and spin filters and provides a way to optimize their performance by means of varying the length of bridging CACs.展开更多
The spin caloritronic properties of the Janus VSTe monolayer were investigated using density functional theory(DFT)and the non-equilibrium Green’s function(NEGF)method,implemented in the Atomistix Toolkit(ATK)package...The spin caloritronic properties of the Janus VSTe monolayer were investigated using density functional theory(DFT)and the non-equilibrium Green’s function(NEGF)method,implemented in the Atomistix Toolkit(ATK)package.Our study revealed significant spin-splitting within the Janus VSTe monolayer,which induced spin currents under a temperature gradient across the device.By applying a 1%tensile strain,the Janus VSTe monolayer exhibited a perfect thermal spin filtering effect(SFE),with the spin-up current nearly suppressed to zero.Both the unstrained and strained Janus VSTe monolayers demonstrated excellent spin caloritronic properties,with spin figures of merit of 10.915 and 8.432 at an average temperature of 100 K,respectively.Notably,these properties were found to be sensitive to temperature,performing optimally at lower temperatures.These results suggest a promising avenue for designing spin caloritronic devices aimed at efficient waste heat recovery.展开更多
We investigated the electric controllable spin-filtering effect in a zigzag phosphorene nanoribbon(ZPNR) based normal–antiferromagnet–normal junction. Two ferromagnets are closely coupled to the edges of the nanorib...We investigated the electric controllable spin-filtering effect in a zigzag phosphorene nanoribbon(ZPNR) based normal–antiferromagnet–normal junction. Two ferromagnets are closely coupled to the edges of the nanoribbon and form the edge-to-edge antiferromagnetism. Under an in-plane electric field, the two degenerate edge bands of the edge-to-edge antiferromagnet split into four spin-polarized sub-bands and a 100% spin-polarized current can be easily induced with the maximal conductance 2e~2/h. The spin polarization changes with the strength of the electric field and the exchange field,and changes sign at opposite electric fields. The spin-polarized current switches from one edge to the other by reversing the direction of the electric field. The edge current can also be controlled spatially by changing the electric potential of the scattering region. The manipulation of edge current is useful in spin-transfer-torque magnetic random-access memory and provides a practical way to develop controllable spintronic devices.展开更多
We present theoretical calculations of spin transport in spin filtering magnetic tunnelling junctions based on the Landauer Biittiker formalism and taking into account the spin-orbit coupling （SOC）. It is shown that...We present theoretical calculations of spin transport in spin filtering magnetic tunnelling junctions based on the Landauer Biittiker formalism and taking into account the spin-orbit coupling （SOC）. It is shown that spin-flip scattering induced by SOC is stronger in parallel alignment of magnetization of the ferromegnet barrier （FB） and the ferromagnetic electrode than that in antiparallel case. The increase of negative tunnelling magnetoresistance with bias is in agreement with recent experimental observation.展开更多
Magneto transport of carriers with a spin-dependent gap in a ferromagnetic-gated bilayer of graphene is investigated.We focus on the effect of an energy gap induced by the mismatch of the exchange fields in the top an...Magneto transport of carriers with a spin-dependent gap in a ferromagnetic-gated bilayer of graphene is investigated.We focus on the effect of an energy gap induced by the mismatch of the exchange fields in the top and bottom layers of an AB-stacked graphene bilayer. The interplay of the electric and exchange fields causes the electron to acquire a spindependent energy gap. We find that, only in the case of the anti-parallel configuration, the effect of a magnetic-induced gap will give rise to perfect spin filtering controlled by the electric field. The resolution of the spin filter may be enhanced by varying the bias voltage. Perfect switching of the spin polarization from ＋100% to -100% by reversing the direction of electric field is predicted. Giant magnetoresistance is predicted to be easily realized when the applied electric field is smaller than the magnetic energy gap. It should be pointed out that the perfect spin filter is due to the layer-dependent exchange energy. This work points to the potential application of bilayer graphene in spintronics.展开更多
Electron spin-polarization modulation with a ferromagnetic strip of in-plane magnetization is analyzed in a hybrid ferromagnet/semiconductor filter device.The dependencies of electron spin-polarization on the strip’s...Electron spin-polarization modulation with a ferromagnetic strip of in-plane magnetization is analyzed in a hybrid ferromagnet/semiconductor filter device.The dependencies of electron spin-polarization on the strip’s magnetization strength,width and position have been systematically investigated.A novel magnetic control spin-polarization switch is proposed by inserting a ferromagnetic metal(FM)strip eccentric in relation to off the center of the spin filter,which produces the first energy level spin-polarization reversal.It is believed to be of significant importance for the realization of semiconductor spintronics multiple-value logic devices.展开更多
The realization of a perfect spin or valley filtering effect in two-dimensional graphene-like materials is one of the fundamental objectives in spintronics and valleytronics. For this purpose, we study spin- and valle...The realization of a perfect spin or valley filtering effect in two-dimensional graphene-like materials is one of the fundamental objectives in spintronics and valleytronics. For this purpose, we study spin- and valley-dependent transport in a silicene system with spatially alternative strains. It is found that due to the valley-opposite gauge field induced by the strain, the strained silicene with a superlattice structure exhibits an angle-resolved valley and spin filtering effect when the spin–orbit interaction is considered. When the interaction that breaks the time reversal symmetry is introduced, such as the spin or valley dependent staggered magnetization, the system is shown to be a perfect spin and valley half metal in which only one spin and valley species is allowed to transport. Our findings are helpful to design both spintronic and valleytronic devices based on silicene.展开更多
Exploring silicon-based spin modulating junction is one of the most promising areas of spintronics.Using nonequilibrium Green's function combined with density functional theory,a set of spin filters of hydrogenate...Exploring silicon-based spin modulating junction is one of the most promising areas of spintronics.Using nonequilibrium Green's function combined with density functional theory,a set of spin filters of hydrogenated zigzag silicene nanoribbons is designed by substituting a silicon atom with a boron one and the spin-correlated transport properties are studied.The results show that the spin polarization can be realized by structural symmetry breaking induced by boron doping.Remarkably,by tuning the edge hydrogenation,it is found that the spin filter efficiency can be varied from 30%to 58%.Moreover,it is also found and explained that the asymmetric hydrogenation can give rise to an obvious negative differential resistance which usually appears at weakly coupled junction.These findings indicate that the boron-doped ZSiNR is a promising material for spintronic applications.展开更多
We study magnetic proximity effect induced low-energy spin transport in the normal/ferromagnetic junction of a semi-infinite zigzag graphene nanoribbon. Due to the absence of a spin flip in a single interface, the spi...We study magnetic proximity effect induced low-energy spin transport in the normal/ferromagnetic junction of a semi-infinite zigzag graphene nanoribbon. Due to the absence of a spin flip in a single interface, the spin transfer in this model can be described by the ＂two-spin channel＂ model. We identify each spin channel as either a perfect conducting or a non-conducting channel. This feature leads to spin filter in symmetric zigzag graphene nanoribbon and spin precession in antisymmetric zigzag graphene nanoribbon, and helps to directly determine the exchange-splitting intensity directly, even without an external auxiliary bias.展开更多
We analyze the transport through asymmetric double quantum dots with an inhomogeneous Zeeman splitting in the presence of crossed dc and ac magnetic fields. A strong spin-polarized current can be obtained by changing ...We analyze the transport through asymmetric double quantum dots with an inhomogeneous Zeeman splitting in the presence of crossed dc and ac magnetic fields. A strong spin-polarized current can be obtained by changing the dc magnetic field. It is mainly due to the resonant tunnelling. But for the ferromagnetic right electrode, the electron spin resonance also plays an important role in transport. We show that the double quantum dots with three-level mixing under crossed dc and ac magnetic fields can act not only as a bipolar spin filter but also as a spin inverter under suitable conditions.展开更多
We theoretically investigate the wave-vector and temperature-dependent electron transport in a magneticnanostructure modulated by an applied bias.The large spin-polarization can be achieved in such a device,and the de...We theoretically investigate the wave-vector and temperature-dependent electron transport in a magneticnanostructure modulated by an applied bias.The large spin-polarization can be achieved in such a device,and the degreeof spin-polarization strongly depends on the transverse wave-vector and the temperature.These interesting propertiesmay be helpful to spin-polarize electrons into semiconductors,and this device may be used as a spin filter.展开更多
EuS is one of typical ferromagnetic semiconductor using as spin filter in spintronic devices,and the doped one could be a good spin injector.Herein,we fabricate a spin-functional tunnel junction by epitaxially growing...EuS is one of typical ferromagnetic semiconductor using as spin filter in spintronic devices,and the doped one could be a good spin injector.Herein,we fabricate a spin-functional tunnel junction by epitaxially growing the ferromagnetic EuS film on Nb-doped SrTiO3.The improvement of Curie temperature up to 35 K is associated with indirect exchange through additional charge carriers at the interface of EuS/Nb:STO junction.Its magnetic field controlled current-voltage curves indicate the large magnetoresistance(MR)effect in EuS barriers as a highly spin-polarized injector.The negative MR is up to 60%in 10-nm EuS/Nb:STO at 4 T and 30 K.The MR is enhanced with increasing thickness of EuS barrier.The large negative MR effect over a wide temperature range makes this junction into a potential candidate for spintronic devices.展开更多
A brief review is presented,which includes the direct current,alternate current,electrical and thermoelectrical transport as well as spin transfer effect in a variety of spin-based nanostructures such as the magnetic ...A brief review is presented,which includes the direct current,alternate current,electrical and thermoelectrical transport as well as spin transfer effect in a variety of spin-based nanostructures such as the magnetic tunnel junction(MTJ),ferromagnet(FM)-quantum dot(QD)/FM-FM,double barrier MTJ,FM-marginal Fermi liquid-FM,FM-unconventional superconductor-FM(FUSF),quantum ring and optical spin-field-effect transistor.The magnetoresistances in those structures,spin accumulation effect in FM-QD-FM and FUSF systems,spin injection and spin filter into semiconductor,spin transfer effect,photon-assisted spin transport,magnonassisted tunneling,electron-electron interaction effect on spin transport,laser-controlled spin dynamics,and thermoelectrical spin transport are discussed.展开更多
In this paper,we present the performance of a recently developed in-situ spin-exchange optically pumped^(3)He-neutron spin filter system at the China Spallation Neutron Source(CSNS).The system achieved a^(3)He polariz...In this paper,we present the performance of a recently developed in-situ spin-exchange optically pumped^(3)He-neutron spin filter system at the China Spallation Neutron Source(CSNS).The system achieved a^(3)He polarization of over 74%at the beamline BL-20.Analysis of neutron transmission experiment results reveals a neutron polarization of>90%and an average transmission of 27%for 2.2Åneutrons,which were maintained for a duration of 120 h of beam time.To the best of our knowledge,this is the first in-situ hyperpolarized^(3)He system incorporated on a neutron beamline in China.This technology is expected to provide stable,wide-angle,and highly polarized neutrons at the CSNS for materials research and fundamental neutron physics.展开更多
A magnetic ground state is revealed for the first time in zigzag-edged carbon nanoscrolls(ZCNSs)from spin-unrestricted density functional theory calculations.Unlike their flat counterpart-zigzag-edged carbon nanoribbo...A magnetic ground state is revealed for the first time in zigzag-edged carbon nanoscrolls(ZCNSs)from spin-unrestricted density functional theory calculations.Unlike their flat counterpart-zigzag-edged carbon nanoribbons,which are semiconductors with spin-degenerate electronic structure-ZCNSs show a variety of magnetic configurations,namely spin-selective semiconductors,metals,semimetals,quasi-half-metals,and half-metals.To the best of our knowledge,this is the first discovery of quasi-half-metals and half-metals in a pure hydrocarbon without resort to an external electric field.In addition,we calculated the spin-dependent transportation of the semiconducting ZCNSs with 12 and 20 zigzag chains,and found that they are 13% and 17% at the Fermi level,respectively,suggesting that ZCNS can be an effective spin filter.展开更多
基金This work is supported by the National Natural Sci-ence Foundation China(No.22173052 of and No.11974217).
文摘Moleculardeviceswith highswitchingperformance and/or the perfect spin filtering effect have always been the pursuit with the development of molecular electronics.Hereb,yusingthe 2001.0V nonequilibrium.Green's function method in combination with the density functionaltheory,the switching performance and spin filtering properties of dimethyldihydropyrene(DHP)/cyclophanediene(CPD)photoswitchable molecule connected by carbon atomic chains(CACs)to two zigzag graphene nanoribbon electrodes have been theoretically investigated.The results show that DHP is more conductive than CPD and therefore an evident switching effect is demonstrated,and the switching ratio(RON/OFF)can reach 4.5×103.It is further revealed that the RoON/OF of DHP/CPD closely depends on the length of CACs.More specifically,the RoN/OFF values of DHP/CPD with odd-numbered CACs are larger than those with even-numbered CACs.More interestingly,a high or even perfect spin filtering effect can be obtained in these investigated DHP/CPD single-molecule devices.Our study is helpful for future design of single-molecule switches and spin filters and provides a way to optimize their performance by means of varying the length of bridging CACs.
基金Project(2022JJ30049)supported by the Natural Science Foundation of Hunan Province,China。
文摘The spin caloritronic properties of the Janus VSTe monolayer were investigated using density functional theory(DFT)and the non-equilibrium Green’s function(NEGF)method,implemented in the Atomistix Toolkit(ATK)package.Our study revealed significant spin-splitting within the Janus VSTe monolayer,which induced spin currents under a temperature gradient across the device.By applying a 1%tensile strain,the Janus VSTe monolayer exhibited a perfect thermal spin filtering effect(SFE),with the spin-up current nearly suppressed to zero.Both the unstrained and strained Janus VSTe monolayers demonstrated excellent spin caloritronic properties,with spin figures of merit of 10.915 and 8.432 at an average temperature of 100 K,respectively.Notably,these properties were found to be sensitive to temperature,performing optimally at lower temperatures.These results suggest a promising avenue for designing spin caloritronic devices aimed at efficient waste heat recovery.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12174077 and 12174051)the Science Foundation of GuangDong Province (Grant No.2021A1515012363)GuangDong Basic and Applied Basic Research Foundation (Grant No.2022A1515110011)。
文摘We investigated the electric controllable spin-filtering effect in a zigzag phosphorene nanoribbon(ZPNR) based normal–antiferromagnet–normal junction. Two ferromagnets are closely coupled to the edges of the nanoribbon and form the edge-to-edge antiferromagnetism. Under an in-plane electric field, the two degenerate edge bands of the edge-to-edge antiferromagnet split into four spin-polarized sub-bands and a 100% spin-polarized current can be easily induced with the maximal conductance 2e~2/h. The spin polarization changes with the strength of the electric field and the exchange field,and changes sign at opposite electric fields. The spin-polarized current switches from one edge to the other by reversing the direction of the electric field. The edge current can also be controlled spatially by changing the electric potential of the scattering region. The manipulation of edge current is useful in spin-transfer-torque magnetic random-access memory and provides a practical way to develop controllable spintronic devices.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10564004)Korea Research Foundation(Grant No. KRF-2005-070-C00065)
文摘We present theoretical calculations of spin transport in spin filtering magnetic tunnelling junctions based on the Landauer Biittiker formalism and taking into account the spin-orbit coupling （SOC）. It is shown that spin-flip scattering induced by SOC is stronger in parallel alignment of magnetization of the ferromegnet barrier （FB） and the ferromagnetic electrode than that in antiparallel case. The increase of negative tunnelling magnetoresistance with bias is in agreement with recent experimental observation.
基金Project supported by the Kasetsart University Research and Development Institute(KURDI)Thailand Research Fund(TRF)(Grant No.TRG5780274)
文摘Magneto transport of carriers with a spin-dependent gap in a ferromagnetic-gated bilayer of graphene is investigated.We focus on the effect of an energy gap induced by the mismatch of the exchange fields in the top and bottom layers of an AB-stacked graphene bilayer. The interplay of the electric and exchange fields causes the electron to acquire a spindependent energy gap. We find that, only in the case of the anti-parallel configuration, the effect of a magnetic-induced gap will give rise to perfect spin filtering controlled by the electric field. The resolution of the spin filter may be enhanced by varying the bias voltage. Perfect switching of the spin polarization from ＋100% to -100% by reversing the direction of electric field is predicted. Giant magnetoresistance is predicted to be easily realized when the applied electric field is smaller than the magnetic energy gap. It should be pointed out that the perfect spin filter is due to the layer-dependent exchange energy. This work points to the potential application of bilayer graphene in spintronics.
基金supported by the National Basic Research Program of China(Grant No.2013CB934003)the State Key Laboratory of Software Development Environment(Grant No.SKLSDE-2013ZX-28)
文摘Electron spin-polarization modulation with a ferromagnetic strip of in-plane magnetization is analyzed in a hybrid ferromagnet/semiconductor filter device.The dependencies of electron spin-polarization on the strip’s magnetization strength,width and position have been systematically investigated.A novel magnetic control spin-polarization switch is proposed by inserting a ferromagnetic metal(FM)strip eccentric in relation to off the center of the spin filter,which produces the first energy level spin-polarization reversal.It is believed to be of significant importance for the realization of semiconductor spintronics multiple-value logic devices.
文摘The realization of a perfect spin or valley filtering effect in two-dimensional graphene-like materials is one of the fundamental objectives in spintronics and valleytronics. For this purpose, we study spin- and valley-dependent transport in a silicene system with spatially alternative strains. It is found that due to the valley-opposite gauge field induced by the strain, the strained silicene with a superlattice structure exhibits an angle-resolved valley and spin filtering effect when the spin–orbit interaction is considered. When the interaction that breaks the time reversal symmetry is introduced, such as the spin or valley dependent staggered magnetization, the system is shown to be a perfect spin and valley half metal in which only one spin and valley species is allowed to transport. Our findings are helpful to design both spintronic and valleytronic devices based on silicene.
基金the National Natural Science Foundations of China(Grant No.11574118)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2019PEM006).
文摘Exploring silicon-based spin modulating junction is one of the most promising areas of spintronics.Using nonequilibrium Green's function combined with density functional theory,a set of spin filters of hydrogenated zigzag silicene nanoribbons is designed by substituting a silicon atom with a boron one and the spin-correlated transport properties are studied.The results show that the spin polarization can be realized by structural symmetry breaking induced by boron doping.Remarkably,by tuning the edge hydrogenation,it is found that the spin filter efficiency can be varied from 30%to 58%.Moreover,it is also found and explained that the asymmetric hydrogenation can give rise to an obvious negative differential resistance which usually appears at weakly coupled junction.These findings indicate that the boron-doped ZSiNR is a promising material for spintronic applications.
文摘We study magnetic proximity effect induced low-energy spin transport in the normal/ferromagnetic junction of a semi-infinite zigzag graphene nanoribbon. Due to the absence of a spin flip in a single interface, the spin transfer in this model can be described by the ＂two-spin channel＂ model. We identify each spin channel as either a perfect conducting or a non-conducting channel. This feature leads to spin filter in symmetric zigzag graphene nanoribbon and spin precession in antisymmetric zigzag graphene nanoribbon, and helps to directly determine the exchange-splitting intensity directly, even without an external auxiliary bias.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10874020 and 11174042)the National Basic Research Program of China (Grants No. 2011CB922204)+1 种基金the CAEP,China (Grant No. 2011B0102024)the SRF for ROCS,SEM,China
文摘We analyze the transport through asymmetric double quantum dots with an inhomogeneous Zeeman splitting in the presence of crossed dc and ac magnetic fields. A strong spin-polarized current can be obtained by changing the dc magnetic field. It is mainly due to the resonant tunnelling. But for the ferromagnetic right electrode, the electron spin resonance also plays an important role in transport. We show that the double quantum dots with three-level mixing under crossed dc and ac magnetic fields can act not only as a bipolar spin filter but also as a spin inverter under suitable conditions.
基金Supported by Hubei Province Key Laboratory of Systems Science in Metallurgical Process (Wuhan University of Science and Technology) under Grant No.C201018 the National Natural Science Foundation of China under Grant No.10805035
文摘We theoretically investigate the wave-vector and temperature-dependent electron transport in a magneticnanostructure modulated by an applied bias.The large spin-polarization can be achieved in such a device,and the degreeof spin-polarization strongly depends on the transverse wave-vector and the temperature.These interesting propertiesmay be helpful to spin-polarize electrons into semiconductors,and this device may be used as a spin filter.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB28000000 and XDB07000000)the National Key Research and Development Program of China(Grant No.2016YFA0300600)the Fund from the Beijing Municipal Science&Technology Commission(Grant No.Z191100007219012).
文摘EuS is one of typical ferromagnetic semiconductor using as spin filter in spintronic devices,and the doped one could be a good spin injector.Herein,we fabricate a spin-functional tunnel junction by epitaxially growing the ferromagnetic EuS film on Nb-doped SrTiO3.The improvement of Curie temperature up to 35 K is associated with indirect exchange through additional charge carriers at the interface of EuS/Nb:STO junction.Its magnetic field controlled current-voltage curves indicate the large magnetoresistance(MR)effect in EuS barriers as a highly spin-polarized injector.The negative MR is up to 60%in 10-nm EuS/Nb:STO at 4 T and 30 K.The MR is enhanced with increasing thickness of EuS barrier.The large negative MR effect over a wide temperature range makes this junction into a potential candidate for spintronic devices.
基金supported in part by the National Science Fund for Distinguished Young Scholars of China(Grant No. 10625419)the National Natural Science Foundation of China(Grant Nos. 90922033 and 10934008)+1 种基金the Ministry of Science and Technology of China (Grant Nos.2012CB932900 and 2013CB933401)the Chinese Academy of Sciences,China,the DFG and the state of Saxony-Anhalt,Germany
文摘A brief review is presented,which includes the direct current,alternate current,electrical and thermoelectrical transport as well as spin transfer effect in a variety of spin-based nanostructures such as the magnetic tunnel junction(MTJ),ferromagnet(FM)-quantum dot(QD)/FM-FM,double barrier MTJ,FM-marginal Fermi liquid-FM,FM-unconventional superconductor-FM(FUSF),quantum ring and optical spin-field-effect transistor.The magnetoresistances in those structures,spin accumulation effect in FM-QD-FM and FUSF systems,spin injection and spin filter into semiconductor,spin transfer effect,photon-assisted spin transport,magnonassisted tunneling,electron-electron interaction effect on spin transport,laser-controlled spin dynamics,and thermoelectrical spin transport are discussed.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFA0406000)National Natural Science Foundation of China(Grant No.11875265)+2 种基金Scientific Instrument Developing Project of the Chinese Academy of Sciences(Grant No.ZDKYYQ20190004)Guangdong Basic and Applied Basic Research Foundation(Grant No.2019B1515120079)Dongguan Introduction Program of Leading Innovative and Entrepreneurial Talents(Grant No.20191122)。
文摘In this paper,we present the performance of a recently developed in-situ spin-exchange optically pumped^(3)He-neutron spin filter system at the China Spallation Neutron Source(CSNS).The system achieved a^(3)He polarization of over 74%at the beamline BL-20.Analysis of neutron transmission experiment results reveals a neutron polarization of>90%and an average transmission of 27%for 2.2Åneutrons,which were maintained for a duration of 120 h of beam time.To the best of our knowledge,this is the first in-situ hyperpolarized^(3)He system incorporated on a neutron beamline in China.This technology is expected to provide stable,wide-angle,and highly polarized neutrons at the CSNS for materials research and fundamental neutron physics.
基金the National Natural Science Foundation of China(NSFC)(Grant Nos.10774003,10474123,10434010,90606023,and 20731160012)National 973 Projects(No.2007CB936200,Ministry of Science and Technology(MOST)of China)Program for New Century Excellent Talents in University of Ministry of Education(MOE)of China,the Grant-in-Aid for National Research Grid Initiative(NAREGI)Nanoscience Project from the Ministry of Education,Sports,Culture,Science and Technology(MEXT)of Japan,the Kurata Memorial Hitachi Science and Technology Foundation,and Nebraska Research Initiative(No.4132050400)of USA.
文摘A magnetic ground state is revealed for the first time in zigzag-edged carbon nanoscrolls(ZCNSs)from spin-unrestricted density functional theory calculations.Unlike their flat counterpart-zigzag-edged carbon nanoribbons,which are semiconductors with spin-degenerate electronic structure-ZCNSs show a variety of magnetic configurations,namely spin-selective semiconductors,metals,semimetals,quasi-half-metals,and half-metals.To the best of our knowledge,this is the first discovery of quasi-half-metals and half-metals in a pure hydrocarbon without resort to an external electric field.In addition,we calculated the spin-dependent transportation of the semiconducting ZCNSs with 12 and 20 zigzag chains,and found that they are 13% and 17% at the Fermi level,respectively,suggesting that ZCNS can be an effective spin filter.
