GaAs原子链耦合石墨烯电子输运性质的理论计算

The theoretical calculation on electron transport properties of GaAs atomic chain coupling graphene ribbon

基于密度泛函理论,运用非平衡格林函数对(GaAs)_4原子链耦合石墨烯纳米条带的电子输运性质进行了第一性原理计算,结果发现通过改变原子链与石墨烯之间的距离可以有效调制系统的电子传输行为.当(GaAs)_4原子链与石墨烯之间的距离d在0.10~0.28nm的范围内变化时,石墨烯、原子链上各自的电子传输要相互影响,且系统的平衡电导在2G_0~7G_0之间发生G_0(G_0=2e^2/h)整数倍的变化,即表现出量子化电导现象;当d>0.28nm时,总的电导等于各自的电导之和,此时(GaAs)_4原子链与石墨烯之间的耦合很弱,各自的电子输运相互影响很小.

The electron transport properties of(GaAs)_4 atomic chain coupling graphene ribbon was calculated using density functional theory and non-equilibrium green's function from the first principles.The results showed that changing the distance of atomic chain with the graphene can modulate electron transport properties of system.As the distance changed in the range of 0.10-0.28 nm,electrons transported in graphene and atomic chain have an influence on each other.The equilibrium conductance of(GaAs)_4 atomic chain coupled with graphene ribbon changed from 2 G_0 to 7 G_0.The results showed that there was phenomenon of quantized conductance.When d>0.28 nm,the coupling effect of atomic chain and the graphene is weak,electrons transported in graphene and atomic chain have a small influence on each other.The total conductance of system is equal to the sum of their respective conductance at this time.