太赫兹场作用下半导体超晶格的动力学过程及光吸收谱研究

J4 ›› 2009, Vol. 26 ›› Issue (4): 482-488.

太赫兹场作用下半导体超晶格的动力学过程及光吸收谱研究

李敏米贤武

吉首大学物理科学与信息工程学院湖南吉首416000

收稿日期:2008-09-02 修回日期:2008-12-22 出版日期:2009-07-28 发布日期:2009-06-29
通讯作者: 米贤武（1973.6-），男，博士，副教授。主要从事低维半导体物理及器件研究工作。
作者简介:李敏（1984.3-），女，山东济南人，吉首大学在读研究生，主要研究方向为低维半导体物理及器件研究。
基金资助:
国家自然科学基金资助项目（10647132）湖南省教育厅资助科研项目（05B014）

Theoretical research on the dynamics process and optical absorption spectra of semiconductor superlattice under the terahertz field

LI Min, MI Xian-Wu

College of physics science and Information Engineering Ji Shou University,Ji Shou 416000,Hunan,China

Received:2008-09-02 Revised:2008-12-22 Published:2009-07-28 Online:2009-06-29

摘要/Abstract

摘要：

基于激子基，采用密度矩阵理论研究了太赫兹场作用下半导体超晶格的子带间动力学过程及光吸收谱。在太赫兹场的驱动下，激子作布洛赫振荡。子带间极化的缓慢变化依赖于太赫兹频率，随着太赫兹频率的增加，子带间极化向下振荡，极化强度降低。以和两种超晶格为例进行研究，它们的光吸收谱出现了卫星峰结构，这是由于太赫兹场与万尼尔斯塔克阶梯激子作用的非线性效应产生的。但是就与超晶格相比而言，我们研究发现，n<0的激子态与n=0的激子态耦合作用较强使得光吸收谱吻合性较好，n＝0时的激子态吸收光谱出现红移，n>0的激子态光吸收谱中出现的边带效应不是很明显。

关键词: 光电子学, 光吸收谱, 密度矩阵理论, 半导体超晶格, 太赫兹电磁波

Abstract:

Using an excitonic basis ,we take the density matrix theory to investigate the intraband dynamics process and optical absorption spectrum of semiconductor superlattice in Terahertz fields.The excitonic Bloch oscillation is driven by the Terahertz field .The slow variation in the intraband polarization depends on the Terahertz frequency, with the increase of Terahertz frequency, the intraband polarization does oscillation downwards and its intensity decrease. Taking and superlattices for examples, because of the nonlinear effect of Terahertz field and WSL excitons, their optical absorption spectrums take on satellite peak structures . However, when we compared these two superlattices in different states, we conclude that the optical absorption spectrum anastomoses well for the strong coupling effect between the excitonic state of n<0 and the state of n=0, while a red shift emerges in the state of n=0 and the sideband effect in the optical absorption spectrum is not very obvious in the state of n>0.

Key words: optical electronics, optical absorption spectrum, density matrix theory, semiconductor superlattice, THZ electromagnetic wave

中图分类号:

李敏米贤武. 太赫兹场作用下半导体超晶格的动力学过程及光吸收谱研究[J]. J4, 2009, 26(4): 482-488.

LI Min, MI Xian-Wu. Theoretical research on the dynamics process and optical absorption spectra of semiconductor superlattice under the terahertz field[J]. J4, 2009, 26(4): 482-488.

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