共查询到16条相似文献,搜索用时 109 毫秒
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从离散的SSH模型出发,考虑了链内的电子相互作用,以及由杂质和周围链上的荷电孤子产生的库仑势的影响,探讨了各种掺杂浓度的反式聚乙炔中孤子晶格的能谱与电子束缚态。计算结果表明:在孤子晶格的能谱中,在价带底有两条定域能级,在导带顶存在着多个电子束缚态,随掺杂浓度的升高,束缚态的局域性减弱,禁带中的孤子能级形成孤子能带。当掺杂浓度高达16.67%时,所有的电子束缚态都消失,转变为扩展态。孤子晶格的禁带宽度随着掺杂浓度的增加而增大,最高占据态与导带底之间的能隙则随之逐渐减小。孤子能带底与价带顶之间的能隙在临界浓度附近有一极大值。还讨论了电子-电子相互作用对孤子晶格能谱的影响。
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在均匀电子气模型下,通过求解Dirac方程,计算了类氢离子束缚态能级能量与等离子体密度的关系,得到了能近似估算能级能量随等离子体密度变化的新拟合公式,该公式同样可以用以估算不同束缚态能级发生压致电离时的临界电子密度.通过与自洽场离子球模型计算结果的比较,作为一种简单和快捷的计算方法,均匀电子汽模型在近似计算束缚态能级能量及压致电离临界电子密度方面是自洽场离子球模型得很好近似方法. 相似文献
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通过在狄拉克方程中考虑德拜休克尔(Debye-Hückel)屏蔽势,研究了类氢离子C5 低能级能量1s(2S1/2),2s(2S1/2),2p(2P1/2和2P3/2)随等离子体电子温度及电子密度的变化规律,计算得到类氢离子C5 能级能量及能级电离势随等离子体环境的变化关系。同时,拟合得到了基于德拜休克尔屏蔽势下相当好的束缚态能级能量随等离子体环境变化的解析公式,利用该公式得到了类氢离子C5 相应各能级发生压致电离的临界电子密度,其结果与其它文献比有很好的可比性。结果表明:束缚态能级能量随等离子体电子温度的升高而减小,随等离子体电子密度的增大而增大。能级能量百分漂移量的对数值与等离子体电子密度的对数值以及等离子体电子温度的对数值之间均呈现出近似线性关系。对计算等离子体电离态分布及光谱模拟具有一定的意义。 相似文献
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He-LiH体系束缚态能级的理论计算 总被引:1,自引:0,他引:1
在CCSD(T) 势能面的基础上,采用严格的量子力学方法计算得到了He-LiH体系束缚态振转能级和波函数,结果表明该体系存在10个振转束缚态.从波函数的分布图中可以知道,与J=0的第一个能级对应的本征态是靠近Li端较深势阱的一个束缚态;第二个能级为伸展激发振动能级;基本上存在于深势阱内,但H端的浅势阱通过隧道效应,对该能级的几率分布产生了影响. 相似文献
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利用级数解法求出一维Schrodinger方程在势-Ze^z/X中的束缚态波函数和能级。结果发现,其能级与1/n^2(n=1,2,3……)成正比,束缚态波函数在原点的值为零,分析了上述结论与关于势-Ze^2/x的能级与1/(n 1/2)^2(n为整数)成正比的结论不相同的原因。 相似文献
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Yuki Obukuro Hiroyuki Nakamura Kenji Obata Shigenori Matsushima Masao Arai Kenkichiro Kobayashi 《Journal of Physics and Chemistry of Solids》2011,72(12):1477-1481
The electronic structure of Sr2Bi2O5 is calculated by the GGA approach. Both of the valence band maximum and the conduction band minimum are located at Γ-point. This means that Sr2Bi2O5 is a direct band-gap material. The wide energy-band dispersions near the valence band maximum and the conduction band minimum predict that holes and electrons generated by band gap excitation have a high mobility. The conduction band is composed of Bi 6p, Sr 4d and O 2p energy states. On the other hand, the valence band can be divided into two energy regions ranging from −9.5 to −7.9 eV (lower valence band) and from −4.13 to 0 eV (upper valence band). The former mainly consists of Bi 6s states hybridizing with O 2s and O 2p states, and the latter is mainly constructed from O 2p states strongly interacting with Bi 6s and Bi 6p states. 相似文献
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We investigated electronic energy structure of vacancy and divacancy in SiO2, and found that oxygen vacancy and divacancy give rise to bound-states near the edge of the conduction band, whereas localized states related to the silicon vacancy occur in the valence band. Our results demonstrate that the doubly occupied oxygen vacancy state yields electrons to silicon in Si-SiO2 junction and serves as a fixed oxide charge. 相似文献
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First-principles calculations, by means of the full-potential augmented plane wave method using the LSDA+U approach (local spin density approximation with Hubbard-U corrections), have been carried out for the electronic structure of the Al0.75Er0.25N. The LSDA+U method is applied to the rare-earth 4? states. We have investigated the electronic and magnetic properties.The Al0.75Er0.25N is shown to be a semiconductor, where the filled ? states are located in the valence bands and the empty ones above the conduction band edge. The magnetic interaction of the rare-earth ion with the host states at the valence and conduction band edges has been investigated and discussed. 相似文献
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We report theoretical investigations on the surface electronic structure of the (110)-face of SnO2, a semiconductor of rutile bulk structure. Starting with a tight binding Hamiltonian for the bulk, we determine the surface electronic structure using the scattering theoretic method. As results we obtain the surface bound states, the surface resonances and the wave-vector resolved surface layer densities of states. The dominant features are two backbond states in the stomach gap of the main valence band and two Sn-s derived states in the lower conduction band region. In the upper valence band region, only weak resonances occur, like in other materials with relatively strong ionicity. 相似文献
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Dan Li Furi Ling Zhenye Zhu Huayu Zhang Xinghong Zhang 《Journal of Physics and Chemistry of Solids》2012,73(5):617-621
The electronic structure, dielectric function, absorption coefficient, and reflectivity of two polycrystalline semiconductors CuAlSe2 and CuAl5Se8 are studied using the density functional theory within the generalized gradient approximation. There are different peaks in the spectra of the imaginary part of the dielectric function. The transitions between the valence bands and conduction bands are discussed at length. In addition, we also notice that the reduced absorption coefficient and reflectivity near band-edge in Cu-poor CuAlSe2 are closely related to a reduction of the density of states near the valence band maximum. 相似文献