摘要
在有效质量近似理论下 ,采用有效垒高方法 ,研究了在沿超晶格生长方向加一有限磁场时磁耦合效应对半无限半导体超晶格中表面电子态的影响 .当考虑超晶格中阱层和垒层之间电子有效质量的差别时 ,沿超晶格生长方向的磁场将导致磁耦合效应的出现 .研究结果表明 ,磁耦合效应不仅引起表面电子能级的量子化 ,而且表面电子能级的大小及其在表面附近的局域程度也依赖于磁场的大小和朗道指数 .此外 ,研究表明布洛赫波数的虚部可以作为一个衡量表面电子态局域程度的物理量 .
A theoretical study, within the effective-mass approximation, on the coupling effects of applied magnetic fields along the growth direction of the superlattice on the surface electron states in a semi-infinite semiconductor superlattice is presented by using an effective-barrier height method. The coupling effect is necessarily considered when the difference of the electron effective masses between different materials cannot be neglected. Our numerical results show that the magneto-coupling effect brings about not only the splitting of the surface electron levels but also the definite dependence of the surface levels and its localization degree on magnetic fields and Landau indices. Our results also indicate that the imaginary component of Bloch wave number can serve as a measure of the localization degree of the surface electron states.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2004年第7期2330-2335,共6页
Acta Physica Sinica
基金
国家自然科学基金 (批准号 :90 2 0 3 0 15 )资助的课题~~
