共查询到17条相似文献,搜索用时 156 毫秒
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本文推导了一般情况下一维j原子链晶格振动的计算模型,并在简谐近似和最近邻近似下获得了晶格的运动方程组。令j=2,3分别计算了一维双原子链及三原子链晶格振动的色散关系,得到了与现有教材及文献相同的结论。本文还讨论了原子质量顺序、恢复力系数顺序等特有晶体结构参数及原子质量大小、恢复力系数大小、晶格常数等一般晶体结构参数对一维三原子链晶格振动色散关系的影响。本文内容可为固体物理教学提供额外的教学素材,帮助学生深入理解晶格振动相关内容,也可为工程上带通滤波器的研发提供一定的参考。 相似文献
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本文以一维j原子链晶格振动为理论计算模型,在简谐近似和最近邻近似下获得其晶格振动方程组,并分别令j=1, 2, 3得到了一维单原子、双原子以及三原子链晶格振动的色散关系,获得了与现有教材及文献中已有的相同结论.结果表明,本文所获得的一维j原子链晶格振动方程组具有一般性.紧接着以该组晶格振动方程组为出发点,通过数值模拟法分析原子间距、恢复力系数及原子质量等晶体结构参数对一维四原子链晶格振动色散关系的影响,进而加深了对固体物理学晶格振动相关内容的理解,并可为工程上带通滤波器的研发提供一定的参考. 相似文献
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采用旋转波近似,讨论一维Klein-Gordon双原子链中的能隙呼吸子. 在驻波边界条件下数值求解一维Klein-Gordon双原子链晶格振动的运动方程组,得到不同耦合系数、不同非线性系数以及不同原子质量比情况下的以重原子为中心的对称模能隙呼吸子. 随着耦合系数的增大,原子之间的耦合作用增强,呼吸子的空间扩展范围增大;非线性作用越大,能隙呼吸子局域化越强;随着原子质量差的增大,呼吸子在空间越来越局域.
关键词:
能隙呼吸子
一维Klein-Gordon双原子链
耦合系数
非线性 相似文献
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对具有在位势且含杂质的一维双原子链的晶格振动方程组进行求解,得到了局域振动的解析解, 给出了在位势对局域振动影响的基本特征,并简要讨论了局域模的存在形式. 相似文献
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不同边界条件下一维双原子链的晶格振动 总被引:10,自引:2,他引:8
在自由边界条件和驻波边界条件下,讨论分析了一维双原子链晶格振动的振动模和色散关系,并与周期性边界条件下的结果进行了比较;明确了在不同边界条件下讨论实际原子链晶格振动的振动模和色散关系,其结果是相同的。 相似文献
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一维双原子链中杂质的局域振动 总被引:2,自引:0,他引:2
讨论了一维双原子链中杂质的局域振动,对杂质原子替代大原子和替代小原子的情况进行了分析,分别得到这两种情况下的高频模和隙模的频率。 相似文献
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I. A. Gospodarev A. V. Grishaev E. S. Syrkin S. B. Feodos’ev 《Physics of the Solid State》2000,42(12):2217-2230
The threshold parameters of defects (the mass defect and the relative change in the force constants) are determined at which local vibrations start to occur in an fcc crystal with substitutional impurities. The characteristics of local vibrations are investigated, and the influence of the defect parameters on the frequency of local vibrations and their decay rate with distance from the impurity atom is analyzed. The frequencies and the intensities of local vibrations are calculated for the nearest neighboring atoms of an impurity, which, combined with the impurity atom, form a defect cluster. 相似文献
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Otto Litzman 《Czechoslovak Journal of Physics》1958,8(6):633-645
Criteria are calculated for the production of localized vibrations in a simple cubic lattice in which one atom is replaced by an impurity atom. The exact criteria are compared with the approximate criteria. 相似文献
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We propose a scheme utilizing a quantum interference phenomenon to switch the transport of atoms in a 1D optical lattice through a site containing an impurity atom. The impurity represents a qubit which in one spin state is transparent to the probe atoms, but in the other acts as a single atom mirror. This allows a single-shot quantum nondemolition measurement of the qubit spin. 相似文献
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The effect of a polarizable impurity atom on the frequency of optical vibrations of a polar crystal is calculated. The impurity-lattice interaction is treated by considering lattice polarization as discrete in contrast to earlier methods based on continuum approximation. In the appropriate limit, our result goes over exactly to the result of earlier approximation. 相似文献
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We study the transport of atoms across a localized Bose-Einstein condensate in a one-dimensional optical lattice. For atoms scattering off the condensate, we predict total reflection as well as full transmission for certain parameter values on the basis of an exactly solvable model. The findings of analytical and numerical calculations are interpreted by a tunable Fano-like resonance and may lead to interesting applications for blocking and filtering atom beams. 相似文献
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C. X. Zhang B. Zhou Y. H. Nie J. Q. Liang J. Liu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(2):161-165
We study the transport of atoms across a localized Bose-Einstein condensate in an onedimensional optical lattice with a single
defect. Our analytical and numerical results show that the defect as well as the nonlinear parameter can control the transmission
of the atoms beam and the position of total reflection caused by Fano resonance. These interesting features may be a very
useful basis for devising tunable atom filters or a button. 相似文献
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《Solid State Communications》1986,59(11):757-760
Presence of a polarizable impurity atom in an ionic crystal induces a localized vibrational mode of the lattice. The frequency of the mode is distinct from the propagating modes of the pure crystal. It is shown in this paper that the frequency of the mode depends on the polarizability of the impurity atom and on the distance of separation between two adjacent impurities. 相似文献