Influence of Integral Instability of Kramers-Kronig Transformation on Photoabsorption Cross Sections

作     者：MA Xiao-Guang GONG Yu-Bing QU Zhao-Jun 

作者机构：Department of Physics Ludong University Yantai 264025 China 

出 版 物：《Communications in Theoretical Physics》 (理论物理通讯（英文版）)

年 卷 期：2009年第52卷第8期

页      面：369-376页

核心收录：

学科分类：080901[工学-物理电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 0704[理学-天文学] 0803[工学-光学工程] 080101[工学-一般力学与力学基础] 0702[理学-物理学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：Supported by the Natural Science Foundations of Ludong University under Grant Nos.22270301 and L20072804 

主　　题：condensed-phase photoabsorption Kramers-Kronig transformation dynamic polarizability 

摘      要：The photoabsorption cross sections of condensed atoms and molecules have proven to be dependent not only on the imaginary parts but also on the real parts of the polarizabilities due to the strong interatomie interactions in condensed environment. The real parts of the polarizabilities calculated usually by using the famous Kramers-Kronig transformation （KKT） from the photoabsorption cross sections of the isolated atoms are very sensitive to the accuracy of the implementation method of the infinite integral in the KKT. The influence of the integral instability of the KKT and the real part of the polarizability on the variation of the photoabsorption cross sections with the number density and the structure of the condensed matter has been studied in the present work for the first time. The conclusion is that the integration method with interpolation has given more reasonable results than the direct truncation method if some appropriate interpolation functions have been used. Some notes and conclusions have also been given for the applications of the alternative coupled expressions of photoabsorption cross sections.