无序度和温度对一维无序体系费米能的影响  

Effects of disorder and temperature on Fermi-energy of one-dimensional disordered systems

作　　者：马松山[1] 徐慧[1] 刘小良[1] 李燕峰[1] 

机构地区：[1]中南大学物理科学与技术学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2007年第2期281-284,共4页Journal of Central South University:Science and Technology

基　　金：高等学校博士点专项科研基金资助项目(20020533001);湖南省自然科学基金资助项目(05JJ40135)

摘　　要：从一维情况出发,采用单电子紧束缚无序模型,建立无序体系一定温度下费米能公式,同时考虑到无序体系中无序这一本质要素,通过数值计算探讨不同无序模式下无序度与体系费米能关系,并进一步探讨温度等对体系费米能的影响。结果表明:无序体系的费米能随无序度的增大而减小,并且非对角无序对体系费米能的影响很大,考虑非对角无序时,体系的费米能大大降低;温度对体系费米能的影响表现为,随温度的升高,体系的费米能相应增大,且在低温区费米能随着温度的升高而增大比较缓慢,而在高温区费米能随着温度的升高而增大较快。Based on tight-binding disordered model describing a single electron band, the Fermi-energy formula at certain temperature of one-dimensional disordered systems was established. By calculating the Fermi-energy of different disordered cases, the effect of the degree of disorder on the Fermi-energy and the temperature dependence of the Fermi-energy were investigated. The results show that the Fermi-energy decreases with increasing the degree of disorder, and the off-diagonal disorder has great effect on the Fermi-energy. When the off-diagonal disorder is considered, the Fermi-energy of system decreases obviously. And the Fermi-energy increases with increasing temperature, showing the characteristics that the Fermi-energy increases slowly at low temperatures, but increases fast at high temperatures.

关 键 词：对角无序 非对角无序 费米能 

分 类 号：O481.3[理学—固体物理]