• Acta Physica Sinica
  • Vol. 69, Issue 7, 076301-1 (2020)
Xiao-Jun Zhang1、*, An-Xiang Wang1, Xiang-An Yan1, and Chang-Le Chen2
Author Affiliations
  • 1School of Science, Xi’an Polytechnic University, Xi’an 710048, China
  • 2School of Science, Northwestern Polytechnical University, Xi’an 710072, China
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    DOI: 10.7498/aps.69.20191910 Cite this Article
    Xiao-Jun Zhang, An-Xiang Wang, Xiang-An Yan, Chang-Le Chen. Application of the modified analytic embedded atomic method in W(100) surface phonon spectrum[J]. Acta Physica Sinica, 2020, 69(7): 076301-1 Copy Citation Text show less

    Abstract

    Based on the theory of surface lattice dynamics, the surface phonon spectrums along three symmetrical directions of $\bar \varGamma \bar L$, $\bar L\bar M$ and $\bar \varGamma \bar M$ are simulated for the W(100) surface by using the modified analytic embedded atom method. The polarization vectors at different symmetrical points are also calculated. According to the criterion and marking method of surface mode, the surface modes along different symmetrical directions are drawn, the distribution range and mode coupling of surface modes are discussed as well. The vibration frequencies of surface modes calculated by us have been compared to available experimental datum and some theoretical values correspondingly. The results display that the present results are general agreement with the referenced experimental or theoretical results. Based on the calculated polarization vector, the surface vibration states are constructed for the atomic layers in the neighboring surface. And the polarization and local features of the surface modes along different symmetrical directions are analyzed. The results show that there are some coupling phenomena between surface mode dispersion, such as avoid crossing and independence crossing. The avoid crossing is found between the surface-mode branch S1 and the surface-mode branch S2 near ${\bar \zeta _y} = 0.32$ along $\bar L\bar M$ direction. In the region, going from $\bar L$ to $\bar M$, S1 changes from y polarization to z polarization, and S2 changes from z polarization to y polarization. The independence crossings exist between surface-mode branch S1 and surface-mode branch S2 at ${\bar \zeta _x} = 0.5$ along $\bar \varGamma \bar L$ direction, and surface-mode branch S2 and surface-mode branch S3 at ${\bar \zeta _x} = 0.5$ along $\bar L\bar M$ direction, respectively. Before and after the crossings, the polarization and local features of the surface modes have not changed. Inspection of the polarization vectors, the coupling phenomena are iconically demonstrated.
    Xiao-Jun Zhang, An-Xiang Wang, Xiang-An Yan, Chang-Le Chen. Application of the modified analytic embedded atomic method in W(100) surface phonon spectrum[J]. Acta Physica Sinica, 2020, 69(7): 076301-1
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