双苯环分子自旋过滤效应第一性原理的研究

Spin Filtering Effect in a Biphenyl Ring from Rirst Principles

分子电子学是近十年来发展起来的一门新兴学科,当器件的尺寸进一步缩小到纳米尺度时,分子电子学有望成为传统电子学的补充甚至替代.利用密度泛函理论与非平衡态格林函数相结合的方法,研究了嵌于石墨烯纳米带电极间的双苯环分子器件的自旋输运性质.研究发现两电极磁矩平行和反平行时,器件有不同的输运性质.电极磁矩平行时出现完美的自旋过滤效应和明显的负微分电阻效应.

Molecular electronics,emerged in the last decade,is as a promising possibility to complement and even to substitute conventional electronics when the size of the device is further reduced to the nanometer scale.In this paper,a combination of density function theory and non-equilibrium Green’s function was used to study the transport properties of the device,which a biphenyl ring connected to graphene nanoribbon electrodes.We found that the device has different transport characteristics in the parallel magnetization configuration and the antiparallel magnetization configuration.The biphenyl ring molecular devices exhibits perfect spin filter effect and negative differential resistance effect.