论文标题
$σ_H$对称和二维晶体系统中的电子相互作用
$σ_h$ symmetry and electron-phonon interaction in two-dimensional crystalline systems
论文作者
论文摘要
电子和声子的耦合由晶体结构的对称特性明智地控制。特别是，对于二维（2D）系统，只要有$σ_H$对称性，电子就不会与纯平面失真的声子夫妇偶联。我们表明，当单位细胞层的成分仅位于$σ_H$对称平面时，这种说明是正确的。这种系统的一个突出的例子是石墨烯。对于那些原子垂直位置远离水平对称平面（例如1H过渡金属二核苷）的2D晶体，声学弯曲模式不会将电子模式与线性顺序相对，而光弯曲的声子（将$σ_H$ symmetry保留）与电子相称。我们的结论得到了分析论证以及使用密度功能扰动理论的数值计算的支持。
The coupling of electrons and phonons is governed wisely by the symmetry properties of the crystal structures. In particular, for two-dimensional (2D) systems, it has been suggested that the electrons do not couple to phonons with pure out-of-plane distortion, as long as there is a $σ_h$ symmetry. We show that such a statement is correct when constituents of the unit-cell layer are only located in the $σ_h$ symmetric plane; a prominent example of such a system is graphene. For those 2D crystals in which atoms are vertically located away from the horizontal symmetric plane (e.g., 1H transition metal dichalcogenides), acoustic flexural modes do not couple to the electrons up to linear order, while optical flexural phonons, which preserve $σ_h$ symmetry, do couple with the electrons. Our conclusions are supported by an analytic argument together with numerical calculations using density functional perturbation theory.
