硅团簇自旋电子器件的理论研究

摘要

利用过渡金属掺杂的硅基团簇，构建了一种自旋分子结；并利用第一性原理方法，对其电子自旋极化输运性质进行了研究。计算表明，通过过渡金属掺杂可以有效地产生自旋极化电流，磁性金属Fe和非磁性金属Cr和Mn掺杂的体系呈现出较明显的自旋极化透射现象，但分子结的自旋极化输运能力与团簇孤立状态下的磁矩无一致性。从Sc到Ni的掺杂，体系的自旋极化透射能力先增大后迅速减小，在Fe掺杂的Si12团簇中出现最大值。%A kind of spintronics is designed by doping the transition metal into Si clusters. Their spin-polarized electron transport properties are investigated by using the first principle analysis. Calculation shows that Fe, Cr and Mn atom doped clusters give the largest spin-polarized transmission coefficients in all the clusters. From Sc to Ni doped clusters, spin filter efficiencies of the systems increase gradually, and the maximal spin filter coefficiency appears in the Fe doped system. The ability to induce the spin-polarized electron transport of the cluster in junction is not cosistent with the magnetic moment of cluster under isolated states.