电子自旋隧穿反平行磁结构的尺度效应  

SCALE EFFECT OF ELECTRON SPIN TUNNELING IN ASYMMETRIC MAGNETIC STRUCTURE

作　　者：袁瑞玚[1] 王如志[1] 段志强[1] 王波[1] 严辉[1] 

机构地区：[1]北京工业大学薄膜材料研究室,北京100022

出　　处：《低温物理学报》2007年第2期136-140,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金(项目编号:50502001;60576012;10604001);北京市自然科学基金(项目编号:2062004);北京市科技新星基金(项目编号:2004A10)资助的课题~~

摘　　要：本文采用转移矩阵法,系统地研究了磁势垒尺度d对磁量子结构中电子自旋输运的影响.结果表明:在理想δ函数型磁势垒结构中,若保持隧穿能量不变,随d的变化,透射系数呈现出明显的正弦或余弦型的周期性振荡,且振荡周期与是否考虑自旋无关.而对于真实δ函数型磁势垒结构,随d的变化,透射系数的周期性振荡的规律明显消失.另外,当电子自旋分别隧穿理想δ函数型磁势垒结构与真实δ函数型磁势垒结构时,隧穿电导随d的变化也存在较大差异.研究结果表明:尺寸的变化对器件的性能产生了较大的影响;且采用理想δ函数型磁势垒结构得出的结论可能了偏离实际应用中的真实δ函数型磁势垒结构的物理规律.In this work, using the transfer matrix method, the effect of magnetic barrier scale on electron spin tunneling in magnetic quantum structure was investigated. The results indicated that for the perfectly simple ideal δ model when the incident energy of electron is invariable, the transmission obviously present sine or cosine periodicity as the magnetic barrier scale d varies, and the periodicity is independent of spin. On the other hand, in case of the realistic δ magnetic barrier the periodicity of transmission is unobvious and nearly disappears. It was also shown that the conductance is very different between the ideal and actual magnetic barriers as the magnetic barriers scale d changes that the capabilities of devices are greatly influenced by theirs scale, and the achieved from the ideal magnetic barriers may not express the physical dependent transport in the realistic magnetic quantum structure. All these phenomena imply theoretical results which are essential of electron spindependent transport in the realistic magnetic quantum structure.

关 键 词：尺度效应 自旋输运 隧穿电导 磁量子结构 

分 类 号：O511[理学—低温物理]