准一维纳米体系中的等离激发

Plasmon excitations in quasi one-dimensional nano-scale systems

摘要:

采用准一维电子气模型,研究了准一维纳米结构体系中的等离激发．利用线性响应理论和电磁场理论等方法,推导出该体系的等离振荡的本征方程,并数值计算该体系的等离激发能谱．结果表明,有限尺度体系中的等离激发能谱表现为分立的形式,并与体系的尺度有很强的依赖关系．各级等离激发的能量随着体系的尺度增加而减小,但等离激发频率个数随体系尺度的增大而增加,等离激发能级间距变得越来越密．此外,等离激元激发能随着电荷密度增加而增大,这和宏观体系的结论定性一致．

Abstract:

Using a quasi-one-dimensional election gas model, we investigate the plasma excitation of quasi-one-dimensional nanostructure systems. The Eigen-equation of plasma oscillation in the quasi-one-dimensional systems is deduced based on the linear-response and electromagnetic theory. Numerical calculation for the plasmon spectrum is presented. The results show that the excitation spectrum of the finite-scale systems is discrete and depending on the size of systems strongly. As the size of system increases, the number of plasmon increases, the excitation spectrum decreases, and the mutual spacing becomes denser. In addition, the excitation spectrum increases with the electron density of the systems increasing, which is qualitatively consistent with the conclusion of macroscopic systems.