利用双势垒结构研究磁场下二维电子的态密度  

STUDY OF DENSITY OF STATES OF TWO-DIMENSIONAL ELECTRON SYSTEM IN MAGNETIC FIELD USING DOUBLE-BARRIER STRUCTURES

作　　者：宋爱民[1] 郑厚植[1] 杨富华[1] 李月霞[1] 李承芳[1] 

机构地区：[1]中国科学院半导体研究所,半导体超晶格国家实验室

出　　处：《红外与毫米波学报》1994年第3期165-172,共8页Journal of Infrared and Millimeter Waves

基　　金：国家攀登计划基金

摘　　要：利用双势垒结构磁电容曲线，测量了垂直磁场下二维电子态密度．采用高斯型朗道态密度模型计算了双势垒结构的电容随磁场的变化曲线，与不同偏压和温度下的实验曲线符合得相当好，由此得到朗道能级模型态密度．根据拟合自洽地给出了二维浓度、费密能级、子带能量和有效Ｌａｎｄｅ因子随磁场振荡变化的规律．The density of states (DOS) of two-dimensional (2D) electrons in perpendicular magnetic fields was reliably extracted from the magneto-capacitive response of double-barrier structures. The model calculations with a Gaussian-like DOS were compared with the experimental C vs. B curves, measured at different biases and temperatures. The results show that the fittings are remarkably good, and the Landau level model DOS is obtained. Unlike the cdnventionally used heterostructure method, the new measurements have no in-plane series magneto-resistance of the two-dimensional channel involved. So, the DOS can be obtained as well even in the quantum Hall regimes. In addition, the physical quantities obtained from the fittings, such as the subband level EO, the Fermi level EF, the 2D number de.nsity N2D and the Lande factor g*, all show oscillatory change with the magnetic field.

关 键 词：朗道能级 态密度 二维电子 双势垒 

分 类 号：O471.5[理学—半导体物理]