碳族单质超导性的第一性原理研究  

First-principles study of superconductivity for the carbon group elements

作　　者：韩沛辰 林永熠 郑磊 刘其军[1] 刘正堂[2] 高娟 HAN Pei-Chen;LIN Yong-Yi;ZHENG Lei;LIU Qi-Jun;LIU Zheng-Tang;GAO Juan(School of Physical Science and Technology,Southwest Jiaotong University,Chengdu 610031,China;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西南交通大学物理科学与技术学院,成都610031 [2]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《原子与分子物理学报》2025年第4期87-92,共6页Journal of Atomic and Molecular Physics

基　　金：西南交通大学大学生创新创业训练计划项目(232117)。

摘　　要：同为第四主族的元素,碳、硅、锗、锡、铅具有相似的价电子排布,但超导性却并不相同.锡和铅在常压下即可实现超导,硅和锗则需要在高压下才具有超导性,而碳的常规晶体结构在常压和高压下均尚未发现其超导性.压力在很大程度上是通过改变晶体结构和原子之间的位置进而影响其超导性,本论文基于密度泛函理论的第一性原理计算,对碳、硅、锗、锡、铅五种第四主族元素的单质的晶体结构、电子结构、声子性质以及超导性质进行系统地对比分析.计算结果表明费米能级附近的电子态密度越高,金属体系实现超导所需的压力越小.在具有金属性的体系中价带靠近费米能级处带隙的存在会使电子更容易局域在费米能级附近,从而增大费米能级附近电子态的数目并提高体系的超导性.此研究为探究超导机制并提高材料的超导性提供思路.Elements of the group IV,carbon,silicon,germanium,tin and lead,have similar valence electron configurations,but with different superconductivity.Tin and lead can achieve superconductivity under normal pressure,silicon and germanium require high pressure to become superconducting,while the superconductivity of the conventional crystal structure of carbon has not been found at both normal pressure and high pressures.Pressure affects superconductivity in large part by changing the crystal structure and the positions of atoms.In this paper,the first-principles calculations based on the density functional theory(DFT)is used to explore the favorable conditions for inducing superconductivity by comparing and analyzing the crystal structures,electronic structures,phonon properties and superconducting properties of five group IV elements(C,Si,Ge,Sn,Pb)systematically.These results indicate that the higher the number of electron states near the Fermi level,the lower the pressure required for the metallic system to achieve superconductivity.Besides,in a metallic system,the existence of a band gap near the Fermi level will make it easier for the electrons to be localized near the Fermi level,thus increasing the number of electron states near the Fermi level and improving the superconductivity.This work provides ideas for revealing the superconducting mechanism and improving the superconductivity of materials.

关 键 词：超导性 第一性原理计算 碳族元素 电子结构 

分 类 号：O56[理学—原子与分子物理]