【摘要】 采用平面波赝势方法计算了MgB2超导薄膜的电子结构.结果发现,表面层B(S)在费米能级处的态密度显著增强.在线性响应的密度泛函微扰理论框架下计算了MgB2薄膜的动力学性质及电—声子相互作用,分析了MgB2超导薄膜在Γ点的振动模的频率.结果发现,MgB2薄膜中的声子存在软化现象,并且声子的软化提高了电-声子相互作用,从而增强了薄膜的超导电性.更多还原

【Abstract】 Using pseudopotential method, the electronic structure of MgB2 film is studied. It is found that the density of states at the Fermi level of the surface B atom has large enhancement. Using the density-functional perturbation theory by the linear response method, the lattice dynamics and the electron-phonon interaction of MgB2 film are studied. The vibrational frequencies at the Γ point of MgB2 film are analyzed. The results show that the phonons in the film become soft, and this softness increases the electron-phonon interaction, resulting in the enhancement of the superconductivity of MgB2 film.更多还原