赝势对计算石墨烯声子谱线的第一性原理研究  

THE INFLUENCE OF THE DIFFERENT PSEUDOPOTENTIALS ON CALCULATIONS OF THE PHONON SPECTRUM FOR GRAPHENE:A FIRST-PRINCIPLES STUDY

作　　者：郭富强 王艳丽[2] 尹国盛 

机构地区：[1]郑州工业应用技术学院,河南郑州451151 [2]河南建筑职业技术学院,河南郑州450007

出　　处：《物理与工程》2016年第5期66-70,共5页Physics and Engineering

基　　金：河南省科技发展计划基础与前沿技术研究项目(项目编号:132300410142);河南省教师教育教改研究项目(项目编号:2014-JSJYYB-008);郑州工业应用技术学院教改项目(项目编号:JG-150029)

摘　　要：石墨烯是理论与实验方面研究的热点,而探究其声子谱线结构又为研究力学、热力学等提供基础.本文采用基于密度泛函理论的第一性原理,运用不同的交换关联和赝势方法,计算了石墨烯以及石墨的声子谱线.对比研究发现:在声子谱低频率阶段,不同的赝势计算的结果差别很小;而在声子谱的高频率阶段,不同赝势计算的结果差别显著.相对于GGA交换关联,LDA交换关联计算的高频光学支有所软化,计算结果与实验值更加接近.相对于US赝势方法,PAW赝势方法计算的结果与实验值更加接近.综合比较,PAW-LDA赝势的计算结果与实验值最为接近.Graphene has great protential in theoretical and experimental studies,and exploring the structure of the phonon spectrum provides a basis for the research of mechanics and thermodynamics.First-principles calculations which based on density functional theory（DFT）have been carried out to study the phonon spectra of graphene and graphite.Our results are consisted with other calculations and experiments.Through comparative analysis,it has been found that for the low frequency,the difference of the phonon structures can be ignored for different pseudopotential;but for the high frequency,the difference is very significant.Compared to GGA pseudopotential,the LDA pseudopotential can give softer frequency;Compared to US pseudopotential,the PAW can give softer frequency.Overall,PAW-LDA can get better phonon structure than other pseudopotential within First-principles framework.These studies provide certain reference for phonon spectra calculation using First-principles method.

关 键 词：声子谱 石墨烯 赝势 

分 类 号：O469[理学—凝聚态物理]