Highly-Polarized Electron Emission from Strain-Compensated Superlattices and Superlattices with High-Valence-Band Splitting.

Rochansky, A. V.

Technical Information Center Oak Ridge Tennessee

关键词: Electron emission;    Superlattices;    Polarized beams;    Indium arsenides;    Aluminium arsenides;   

RP-ID  :  DE2004826800

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Strained layer heterostructure and short-period superlattice structures have been used to advantage in achieving highly spin-polarized electron photoemission. The strain-induced splitting of the valence band at the band-gap minimum provides a high electron polarization in the conduction band under excitation by circularly polarized light. Smearing of the interband absorption edge and the hole scattering processes lead to polarization in the band-edge absorption of less than 100%, polarization losses being typically about 6%. This mechanism sets a limit on the maximum polarization of emitted electrons. The initial polarization can be increased by choosing structures with a higher valence band splitting.