双碳链体系中自旋过滤效应的第一性原理研究

摘要

The spin filtering phenomenon in double carbon wires system by first principles study along with density functional theory has been studied.A junction of double carbon atomic wires coupled to zigzag graphene nanoribbon electrodes are chosen as this model,where the width of zigzag graphene nanoribbon electrodes is 12.The paper find that fine spin filtering effect exists in the double carbon wires system,which is better than that in the single carbon wires system.Spin filtering phenomenon does not exist in the antiparallel case of single carbon wires system,but things happen differently in antiparallel case of double carbon wires system with fine spin filtering effect.In other words,perfect spin filtering effect 100% exist in both the parallel and antiparallel cases of double carbon wires system,which demonstrates that the device double carbon wires system can be used as spin filtering electronic devices.%采用第一性原理密度泛函理论方法研究了平行放置的双碳原子链体系中的自旋输运情况.将双碳原子链置于12个宽度锯齿型石墨烯纳米带组成的双电极中,研究发现:双碳原子链体系中的自旋过滤效果优于单条碳原子链体系中的自旋过滤效果;更重要的是,在单条碳原子链体系中,当左右电极磁性反平行时,没有自旋过滤效果,双碳链结构彻底改变了单碳链体系中这种情况,即在双碳链体系中,不管2个电极的磁性是平行结构还是反平行结构,自旋过滤效果都近100%,是非常好的自旋过滤电子器件.