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Band structures of strained kagome lattices
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作者 徐露婷 杨帆 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期456-463,共8页
Materials with kagome lattices have attracted significant research attention due to their nontrivial features in energy bands.We theoretically investigate the evolution of electronic band structures of kagome lattices... Materials with kagome lattices have attracted significant research attention due to their nontrivial features in energy bands.We theoretically investigate the evolution of electronic band structures of kagome lattices in response to uniaxial strain using both a tight-binding model and an antidot model based on a periodic muffin-tin potential.It is found that the Dirac points move with applied strain.Furthermore,the flat band of unstrained kagome lattices is found to develop into a highly anisotropic shape under a stretching strain along y direction,forming a partially flat band with a region dispersionless along ky direction while dispersive along kx direction.Our results shed light on the possibility of engineering the electronic band structures of kagome materials by mechanical strain. 展开更多
关键词 kagome lattice STRAIN band structure engineering
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Experimental observation of Fermi-level flat band in novel kagome metal CeNi_(5)
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作者 陈学智 王乐 +7 位作者 张帅 张任杰 程以伟 胡裕栋 孟承诺 刘正太 吕佰晴 黄耀波 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期467-472,共6页
Kagome materials are a class of material with a lattice structure composed of corner-sharing triangles that produce various exotic electronic phenomena,such as Dirac fermions,van Hove singularities,and flat bands.Howe... Kagome materials are a class of material with a lattice structure composed of corner-sharing triangles that produce various exotic electronic phenomena,such as Dirac fermions,van Hove singularities,and flat bands.However,most of the known kagome materials have a flat band detached from the Fermi energy,which limits the investigation of the emergent flat band physics.In this work,by combining soft x-ray angle-resolved photoemission spectroscopy(ARPES)and the first-principles calculations,the electronic structure is investigated of a novel kagome metal CeNi_(5) with a clear dispersion along the kz direction and a Fermi level flat band in theΓ–K–M–Γplane.Besides,resonant ARPES experimental results indicate that the valence state of Ce ions is close to 4^(+),which is consistent with the transport measurement result.Our results demonstrate the unique electronic properties of CeNi_(5) as a new kagome metal and provide an ideal platform for exploring the flat band physics and the interactions between different types of flat bands by tuning the valence state of Ce ions. 展开更多
关键词 ARPES kagome lattice band structure flat band
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Reanalysis of energy band structure in the type-II quantum wells
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作者 李欣欣 邓震 +4 位作者 江洋 杜春花 贾海强 王文新 陈弘 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期75-78,共4页
Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures... Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures, the energy of carriers in the well splits into discrete energy levels due to the confinement of barriers in the growth direction. However, the discrete energy levels obtained at a fixed wave vector cannot accurately reflect the actual energy band structure. In this work, the band structure of the type-II quantum wells is reanalyzed. When the wave vectors of the entire Brillouin region(corresponding to the growth direction) are taken into account, the quantized energy levels of the carriers in the well are replaced by subbands with certain energy distributions. This new understanding of the energy bands of low-dimensional structures not only helps us to have a deeper cognition of the structure, but also may overturn many viewpoints in traditional band theories and serve as supplementary to the band theory of low-dimensional systems. 展开更多
关键词 energy band structure type-II quantum wells low-dimensional semiconductors
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Optimizing band structure of CoP nanoparticles via rich-defect carbon shell toward bifunctional electrocatalysts for overall water splitting 被引量:7
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作者 Juncheng Wu Zhe‐Fan Wang +7 位作者 Taotao Guan Guoli Zhang Juan Zhang Jie Han Shengqin Guan Ning Wang Jianlong Wang Kaixi Li 《Carbon Energy》 SCIE CSCD 2023年第3期112-125,共14页
Transition-metal phosphides(TMPs)with high catalytic activity are widely used in the design of electrodes for water splitting.However,a major challenge is how to achieve the trade-off between activity and stability of... Transition-metal phosphides(TMPs)with high catalytic activity are widely used in the design of electrodes for water splitting.However,a major challenge is how to achieve the trade-off between activity and stability of TMPs.Herein,a novel method for synthesizing CoP nanoparticles encapsu-lated in a rich-defect carbon shell(CoP/DCS)is developed through the self-assembly of modified polycyclic aromatic molecules.The graft and removal of high-activity C-N bonds of aromatic molecules render the controllable design of crystallite defects of carbon shell.The density functional theory calculation indicates that the carbon defects with unpaired electrons could effectively tailor the band structure of CoP.Benefiting from the improved activity and corrosion resistance,the CoP/DCS delivers outstanding difunctional hydrogen evolution reaction(88 mV)and oxygen evolution reaction(251 mV)performances at 10 mA cm^(−2)current density.Furthermore,the coupled water electrolyzer with CoP/DCS as both the cathode and anode presents ultralow cell voltages of 1.49 V to achieve 10 mA cm^(−2)with long-time stability.This strategy to improve TMPs electrocatalyst with rich-DCS and heterogeneous structure will inspire the design of other transition metal compound electrocatalysts for water splitting. 展开更多
关键词 band structure bifunctional electrocatalysts CoP nanoparticles overall water splitting rich‐defect carbon
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Three-dimensional simulation of a Ka-band relativistic Cherenkov source with metal photonic-band-gap structures 被引量:9
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作者 高喜 杨梓强 +4 位作者 亓丽梅 兰峰 史宗君 李大治 梁正 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第6期2452-2458,共7页
This paper presents a three-dimensional particle-in-cell (PIC) simulation of a Ka-band relativistic Cherenkov source with a slow wave structure (SWS) consisting of metal photonic band gap (PBG) structures. In th... This paper presents a three-dimensional particle-in-cell (PIC) simulation of a Ka-band relativistic Cherenkov source with a slow wave structure (SWS) consisting of metal photonic band gap (PBG) structures. In the simulation, a perfect match layer boundary is employed to absorb passing band modes supported by the PBG lattice with an artificial metal boundary. The simulated axial field distributions in the cross section and surface of the SWS demonstrate that the device operates in the vicinity of the π point of a TM01-1ike mode. The Fourier transformation spectra of the axial fields as functions of time and space show that only a single frequency appears at 36.27 GHz, which is in good agreement with that of the intersection of the dispersion curve with the slow space charge wave generated on the beam. The simulation results demonstrate that the SWS has good mode selectivity. 展开更多
关键词 Cherenkov source slow wave structure photonic band gap three-dimensional particlein-cell
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Photonic band structures of two-dimensional photonic crystals with deformed lattices 被引量:4
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作者 蔡向华 郑婉华 +2 位作者 马小涛 任刚 夏建白 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第12期2507-2513,共7页
Using the plane-wave expansion method, we have calculated and analysed the changes of photonic band structures arising from two kinds of deformed lattices, including the stretching and shrinking of lattices. The squar... Using the plane-wave expansion method, we have calculated and analysed the changes of photonic band structures arising from two kinds of deformed lattices, including the stretching and shrinking of lattices. The square lattice with square air holes and the triangular lattice with circular air holes are both studied. Calculated results show that the change of lattice size in some special ranges can enlarge the band gap, which depends strongly on the filling factor of air holes in photonic crystals; and besides, the asymmetric band edges will appear with the broken symmetry of lattices. 展开更多
关键词 photonic band gap photonic crystal plane-wave expansion method
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Decade Milestone Advancement of Defect-Engineered g-C_(3)N_(4) for Solar Catalytic Applications 被引量:3
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作者 Shaoqi Hou Xiaochun Gao +8 位作者 Xingyue Lv Yilin Zhao Xitao Yin Ying Liu Juan Fang Xingxing Yu Xiaoguang Ma Tianyi Ma Dawei Su 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第4期153-218,共66页
Over the past decade, graphitic carbon nitride(g-C_(3)N_(4)) has emerged as a universal photocatalyst toward various sustainable carbo-neutral technologies. Despite solar applications discrepancy, g-C_(3)N_(4) is stil... Over the past decade, graphitic carbon nitride(g-C_(3)N_(4)) has emerged as a universal photocatalyst toward various sustainable carbo-neutral technologies. Despite solar applications discrepancy, g-C_(3)N_(4) is still confronted with a general fatal issue of insufficient supply of thermodynamically active photocarriers due to its inferior solar harvesting ability and sluggish charge transfer dynamics. Fortunately, this could be significantly alleviated by the “all-in-one” defect engineering strategy, which enables a simultaneous amelioration of both textural uniqueness and intrinsic electronic band structures. To this end, we have summarized an unprecedently comprehensive discussion on defect controls including the vacancy/non-metallic dopant creation with optimized electronic band structure and electronic density, metallic doping with ultraactive coordinated environment(M–N_(x), M–C_(2)N_(2), M–O bonding), functional group grafting with optimized band structure, and promoted crystallinity with extended conjugation π system with weakened interlayered van der Waals interaction. Among them, the defect states induced by various defect types such as N vacancy, P/S/halogen dopants, and cyano group in boosting solar harvesting and accelerating photocarrier transfer have also been emphasized. More importantly, the shallow defect traps identified by femtosecond transient absorption spectra(fs-TAS) have also been highlighted. It is believed that this review would pave the way for future readers with a unique insight into a more precise defective g-C_(3)N_(4) “customization”, motivating more profound thinking and flourishing research outputs on g-C_(3)N_(4)-based photocatalysis. 展开更多
关键词 Defect engineering g-C_(3)N_(4) Electronic band structures Photocarrier transfer kinetics Defect states
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Syntheses,Structures and Band Gaps of KLnSiS_4(Ln=Sm,Yb) 被引量:3
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作者 郭胜平 曾卉一 +3 位作者 郭国聪 邹建平 徐刚 黄锦顺 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第12期1543-1548,共6页
Two new quaternary sulfides, KSmSiS4 (1) and KYbSiS4 (2), have been synthesized by high-temperature solid-state reaction. Single,crystal X-ray diffraction analyses indicate that both compounds crystallize in the s... Two new quaternary sulfides, KSmSiS4 (1) and KYbSiS4 (2), have been synthesized by high-temperature solid-state reaction. Single,crystal X-ray diffraction analyses indicate that both compounds crystallize in the space group P21/m, and the crystal data are as follows: a = 6.426(11), b = 6.582(11), c = 8.602(15)A, β= 107.90(13)°, Z = 2, V= 346.2(10) A^3, Dc = 3.317 g/cm^3, F(000) = 318,μ(MoKα) = 10.334 mm^-1, the final R = 0.0559 and wR = 0.1370 for 1; and α= 6.3244(10), b = 6.5552(10), c = 8.5701(15)A, β= 108.001(13)°, Z = 2, V = 337.91(9) A^3, De= 3.621 g/cm^3, F(000) = 334, μ(MoKα) = 15.737 mm^-1, the final R = 0.0422 and wR = 0.0960 for 2. The KLnSiS4 (Ln = Sm, Yb) structure consists of corrugated ∞^2 [LnSiS4]^- layers which are formed by edge-sharing LnS8 bicapped trigonal prisms and SiS4 tetrahedra. The K^+ cations are located in the cavities defined by S2 anions between the ∞^2[LnSiS4]^- layers. Band-gap analyses show that compounds 1 and 2 are semiconductors with optical band-gaps of 2.40 and 2.34 eV, respectively. 展开更多
关键词 CHALCOGENIDE RARE-EARTH solid-state reaction crystal structure band gap
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Band structures of TiO_2 doped with N, C and B 被引量:6
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作者 XU Tian-hua SONG Chen-lu LIU Yong HAN Gao-rong 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2006年第4期299-303,共5页
This study on the band structures and charge densities of nitrogen (N)-, carbon (C)- and boron (B)-doped titanium dioxide (TiO2) by first-principles simulation with the CASTEP code (Segall et al., 2002) showed that th... This study on the band structures and charge densities of nitrogen (N)-, carbon (C)- and boron (B)-doped titanium dioxide (TiO2) by first-principles simulation with the CASTEP code (Segall et al., 2002) showed that the three 2p bands of im-purity atom are located above the valence-band maximum and below the Ti 3d bands, and that along with the decreasing of im-purity atomic number, the fluctuations become more intensive. We cannot observe obvious band-gap narrowing in our result. Therefore, the cause of absorption in visible light might be the isolated impurity atom 2p states in band-gap rather than the band-gap narrowing. 展开更多
关键词 CASTEP code Titanium dioxide band structure Charge density
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Synthesis and Crystal and Band Structures of YbCu_6In_6 with 3D Framework 被引量:2
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作者 雷晓武 岳呈阳 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第3期389-395,共7页
A new intermetallic compound,YbCu6In6,has been synthesized by solid-state reaction of the corresponding pure elements in a welded tantalum tube at high temperature.Its crystal structure was established by single-cryst... A new intermetallic compound,YbCu6In6,has been synthesized by solid-state reaction of the corresponding pure elements in a welded tantalum tube at high temperature.Its crystal structure was established by single-crystal X-ray diffraction.YbCu6In6 crystallizes in tetragonal space group I4/mmm with a = 9.2283(5),c = 5.4015(4),V = 460.00(5) 3,Z = 2,Mr = 1243.20,Dc = 8.976 g/cm3,μ = 38.243 mm-1,F(000) = 1076,and the final R = 0.0258 and wR = 0.0602 for 173 observed reflections with I 〉 2σ(I).The structure of YbCu6In6 belongs to the ThMn12 type.It is isostructural with RECu6In6(RE = Y,Ce,Pr,Nd,Gd,Tb,Dy),containing one-dimensional(1D) [Cu10In6] cluster chain along the c axis,which is interconnected via sharing the Cu(1) atoms to form a three-dimensional(3D) [Cu6In6] framework with Yb atoms encapsulated in the 1D tunnels along the c axis.Band structure calculations based on Density Functional Theory(DFT) method indicate that YbCu6In6 is metallic. 展开更多
关键词 INTERMETALLIC INDIDES crystal structure band structure calculation
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Band structures of transverse waves in nanoscale multilayered phononic crystals with nonlocal interface imperfections by using the radial basis function method 被引量:2
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作者 Zhizhong Yan Chunqiu Wei Chuanzeng Zhang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2017年第2期415-428,共14页
A radial basis function collocation method based on the nonlocal elastic continuum theory is developed to compute the band structures of nanoscale multilayered phononic crystals. The effects of nonlocal imperfect inte... A radial basis function collocation method based on the nonlocal elastic continuum theory is developed to compute the band structures of nanoscale multilayered phononic crystals. The effects of nonlocal imperfect interfaces on band structures of transverse waves propagating obliquely or vertically in the system are studied. The correctness of the present method is verified by comparing the numerical results with those obtained by applying the transfer matrix method in the case of nonlocal perfect interface. Furthermore, the influences of the nanoscale size, the impedance ratio and the incident angle on the cut-off frequency and band structures are investigated and discussed in detail. Numerical results show that the nonlocal interface imperfections have significant effects on the band structures in the macroscopic and microscopic scale. 展开更多
关键词 Radial basis function Phononic crystal NANOSCALE band structure Nonlocal imperfect interface
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Engineering Thermoelectric Performance of α-GeTe by Ferroelectric Distortion 被引量:1
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作者 Yuting Fan Chenghao Xie +5 位作者 Jun Li Xiangyu Meng Jinchang Sun Jinsong Wu Xinfeng Tang Gangjian Tan 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第2期171-179,共9页
The rhombohedralα-GeTe can be approximated as a slightly distorted rock-salt structure along its[111]direction and possesses superb thermoelectric performance.However,the role of such a ferroelectric-like structural ... The rhombohedralα-GeTe can be approximated as a slightly distorted rock-salt structure along its[111]direction and possesses superb thermoelectric performance.However,the role of such a ferroelectric-like structural distortion on its transport properties remains unclear.Herein,we performed a systematic study on the crystal structure and electronic band structure evolutions of Ge_(1-x)Sn_(x)Te alloys where the degree of ferroelectric distortion is continuously tuned.It is revealed that the band gap is maximized while multiple valence bands are converged at x=0.6,where the ferroelectric distortion is the least but still works.Once undistorted,the band gap is considerably reduced,and the valence bands are largely separated again.Moreover,near the ferro-to-paraelectric phase transition Curie temperature,the lattice thermal conductivity reaches its minima because of significant lattice softening enabled by ferroelectric instability.We predict a peak ZT value of 2.6 at 673 K inα-GeTe by use of proper dopants which are powerful in suppressing the excess hole concentrations but meanwhile exert little influence on the ferroelectric distortion. 展开更多
关键词 electronic band structures ferroelectric distortion lattice softening THERMOELECTRIC α-GeTe
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Photonic band structures of quadrangular multiconnected networks 被引量:1
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作者 宋欢欢 杨湘波 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第7期313-321,共9页
By means of the network equation and generalized dimensionless Floquet-Bloch theorem, this paper investigates the properties of the band number and width for quadrangular multiconnected networks (QMNs) with a differ... By means of the network equation and generalized dimensionless Floquet-Bloch theorem, this paper investigates the properties of the band number and width for quadrangular multiconnected networks (QMNs) with a different number of connected waveguide segments (NCWSs) and various matching ratio of waveguide length (MRWL). It is found that all photonic bands are wide bands when the MRWL is integer. If the integer attribute of MRWL is broken, narrow bands will be created from the wide band near the centre of band structure. For two-segment-connected networks and three-segment-connected networks, it obtains a series of formulae of the band number and width. On the other hand, it proposes a so-called concept of two-segment-connected quantum subsystem and uses it to discuss the complexity of the band structures of QMNs. Based on these formulae, one can dominate the number, width and position of photonic bands within designed frequencies by adjusting the NCWS and MRWL. There would be potential applications for designing optical switches, optical narrow-band filters, dense wavelength-division-multiplexing devices and other correlative waveguide network devices. 展开更多
关键词 multiconnected network WAVEGUIDE photonic band structure
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Interface-induced topological phase and doping-modulated bandgap of two-dimensioanl graphene-like networks
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作者 杨柠境 杨海 金国钧 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第1期434-439,共6页
Biphenylene is a new topological material that has attracted much attention recently.By amplifying its size of unit cell,we construct a series of planar structures as homogeneous carbon allotropes in the form of polyp... Biphenylene is a new topological material that has attracted much attention recently.By amplifying its size of unit cell,we construct a series of planar structures as homogeneous carbon allotropes in the form of polyphenylene networks.We first use the low-energy effective model to prove the topological three periodicity for these allotropes.Then,through first-principles calculations,we show that the topological phase has the Dirac point.As the size of per unit cell increases,the influence of the quaternary rings decreases,leading to a reduction in the anisotropy of the system,and the Dirac cone undergoes a transition from type II to type I.We confirm that there are two kinds of non-trivial topological phases with gapless and gapped bulk dispersion.Furthermore,we add a built-in electric field to the gapless system by doping with B and N atoms,which opens a gap for the bulk dispersion.Finally,by manipulating the built-in electric field,the dispersion relations of the edge modes will be transformed into a linear type.These findings provide a hopeful approach for designing the topological carbon-based materials with controllable properties of edge states. 展开更多
关键词 POLYPHENYLENE interface band structure Zak phase edge state
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Size effect on light propagation modulation near band edges in one-dimensional periodic structures
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作者 唐洋 王佳俊 +2 位作者 赵星棋 李同宇 石磊 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期421-424,共4页
Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attr... Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attracted wide attention.However,the practically fabricated structures can only have finite size,i.e.,limited numbers of periods,leading to changes of the light propagation modulation compared with infinite structures.Here,we study the size effect on light localization and near-zero refractive-index propagation near band edges in one-dimensional periodic structures.Near edges of the band gap,as the structure's size shrinks,the broadening of the band gap and the weakening of the light localization are discovered.When the size is small,an added layer on the surface will perform large modulation in the group velocity.Near the degenerate point with Dirac-like dispersion,the zero-refractive-index effects like the zero-phase difference and near-unity transmittance retain as the size changes,while absolute group velocity fluctuates when the size shrinks. 展开更多
关键词 one-dimensional(1D)photonic crystal finite-size effect band gap light localization zerorefractive-index effect
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Band Structures and Two-photon Absorption of ZnGeP_2 and AgGaS_2 Crystals 被引量:1
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作者 程文旦 谢知 +3 位作者 吴东升 黄淑萍 王金云 张浩 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第6期950-956,共7页
Band structure and bonding properties have been investigated in terms of periodic density functional theory(DFT) method,and two-photon absorption(TPA) spectra have been simulated by two-band model for ZnGeP2 and A... Band structure and bonding properties have been investigated in terms of periodic density functional theory(DFT) method,and two-photon absorption(TPA) spectra have been simulated by two-band model for ZnGeP2 and AgGaS2 crystals.It has been predicted that the AgGaS2 crystal has a wider window of nonlinear transmission,and the laser pumping energy larger than 1.02 and 1.35 eV will lead to deleterious TPA of higher nonlinear effect for ZnGeP2 and AgGaS2 crystals,respectively.Electron origin of TPA for them is also discussed. 展开更多
关键词 DFT band structure TPA electron transition
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Band gap analysis of periodic structures based on cell experimental frequency response functions(FRFs) 被引量:1
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作者 Li-Jie Wu Han-Wen Song 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2019年第1期156-173,I0005,共19页
An approach is proposed to estimate the transfer function of the periodic structure, which is known as an absorber due to its repetitive cells leading to the band gap phenomenon. The band gap is a frequency range in w... An approach is proposed to estimate the transfer function of the periodic structure, which is known as an absorber due to its repetitive cells leading to the band gap phenomenon. The band gap is a frequency range in which vibration will be inhibited. A transfer function is usually performed to gain band gap. Previous scholars regard estimation of the transfer function as a forward problem assuming known cell mass and stiffness matrices. However, the estimation of band gap for irregular or complicated cells is hardly accurate because it is difficult to model the cell exactly. Therefore, we treat the estimation as an inverse problem by employing modal identification and curve fitting. A transfer matrix is then established by parameters identitled through modal analysis. Both simulations and experiments have been performed. Some interesting conclusions about the relationship between modal parameters and band gap have been achieved. 展开更多
关键词 band GAP MODAL ANALYSIS Parameter identification PERIODIC structure Transfer matrix
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Design of Novel Compact Electromagnetic Bandgap Structures with Enhanced Bandwidth 被引量:1
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作者 Ping Jiang Kang Xie 《Journal of Electronic Science and Technology》 CAS 2010年第3期262-266,共5页
Two kinds of compact electromagnetic band gap (EBG) structures are designed. A two layer compact EBG structure configured with cross spiral shape line inductors and interdigital capacitors is first presented. Becaus... Two kinds of compact electromagnetic band gap (EBG) structures are designed. A two layer compact EBG structure configured with cross spiral shape line inductors and interdigital capacitors is first presented. Because of its significantly enlarged equivalent inductor and capacitance, the period of the lattice is approximately 4.5% of the free space wavelength. By insetting several narrow slits in the ground plane, the bandwidth of the main bandgap is enhanced by nearly 19%. Further effort has been made for designing a three layer compact EBG structure. Simulation results show that its period is reduced by about 26% compared to that of proposed two layer EBG structure, and the bandwidth of the main bandgap is about 3 times as that of the proposed two layer EBG structure. The detailed designs including a two layer compact 3×7 EBG array with and without defect ground plane and the three layer EBG array are given and simulation results are presented. 展开更多
关键词 Defect ground electromagnetic band gap high surface surface wave. structure impedance
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Quasiparticle Band Structures of Defects in Anatase TiO2 Bulk
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作者 陈廷威 郝亚南 马玉臣 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2017年第6期771-775,I0003,共6页
Quasiparticle band structures of the defective anatase TiO2 bulk with O vacancy, Ti interstitial and H interstitial are investigated by the GW method within many-body Green's function theory. The computed direct band... Quasiparticle band structures of the defective anatase TiO2 bulk with O vacancy, Ti interstitial and H interstitial are investigated by the GW method within many-body Green's function theory. The computed direct band gap of the perfect anatase bulk is 4.3 eV, far larger than the experimental optical absorption edge (3.2 eV). We found that this can be ascribed to the inherent defects in anatase which drag the conduction band (CB) edge down. The occupied band-gap states induced by these defects locate close to the CB edge, exclud- ing the possible contribution of these bulk defects to the deep band-gap state below CB as observed in experiments. 展开更多
关键词 Anatase TiO2 DEFECT GW method band structure Optical absorption edge
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Excitation of defect modes from the extended photonic band-gap structures of 1D photonic lattices 被引量:2
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作者 周可雅 郭忠义 +1 位作者 Muhammad Ashfaq Ahmad 刘树田 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第1期284-288,共5页
This paper stuides numerically the model equation in a one dimensional defective photonic lattice by modifying the potential function to a periodic function. It is found that defect modes (DMs) can be regarded as Bl... This paper stuides numerically the model equation in a one dimensional defective photonic lattice by modifying the potential function to a periodic function. It is found that defect modes (DMs) can be regarded as Bloch modes which are excited from the extended photonie band-gap structure at Bloch wave-numbers with kx = 0. The DMs for both positive and negative defects are considered in this method. 展开更多
关键词 optical-induced photonic lattices photonic band-gaps defect modes
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