Complex band structure and tunneling through ferromagnet /Insulator /Ferromagnet junctions
Complex band structure and tunneling through ferromagnet /Insulator /Ferromagnet junctions
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DOI：
10.1103/physrevlett.85.1088
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发表时间：
2000-07
影响因子：
8.6
通讯作者：
P. Mavropoulos;N. Papanikolaou;P. Dederichs
中科院分区：
文献类型：
--
作者：
P. Mavropoulos;N. Papanikolaou;P. Dederichs
我们研究了金属诱导的间隙态对金属电子隧穿外延绝缘膜的重要性。通过在波矢中引入一个虚部kappa来描述波函数在绝缘体中的衰减，我们得到了差距区的复杂能带结构。计算了半导体Si、Ge、GaAs和ZnSe的衰变参数kappa谱。在大多数情况下，对于足够大的膜厚度的隧道是占主导地位的界面上的垂直入射状态。考虑可能的例外情况。在此基础上，我们讨论了Fe/半导体/Fe（001）结中的自旋相关隧穿。
We investigate the importance of metal-induced gap states for the tunneling of metal electrons through epitaxial insulator films. By introducing an imaginary part kappa to the wave vector in order to describe the decay of the wave function in the insulator, we obtain the complex band structure in the gap region. The spectrum of the decay parameters kappa is calculated for the semiconductors Si, Ge, GaAs, and ZnSe. In most cases, for large enough film thicknesses the tunneling is dominated by states of normal incidence on the interface. Possible exceptions are considered. Based on our conclusions, we discuss the spin-dependent tunneling in Fe/semiconductor/Fe (001) junctions.