混合碳链的电子输运特性的第一性原理研究

Study on the Transport Properties of a Adulterant Carbon Wire——The First Principles Calculation

用第一性原理非平衡格林函数方法研究了混合碳链置于两个Al(100)电极之间的输运性质.计算了IV族原子硅取代一维纯碳链中不同位置碳原子,以及硅取代不同长度的碳链时的输运性质,同时比较了其他非IV族原子N、P、S分别取代C7碳链中不同碳原子的输运性质.研究结果表明,对于混合碳链同样存在平衡电导的奇偶振荡,并且随着取代的位置不同,也会有奇偶振荡现象.硅原子取代碳原子后对体系的透射谱、不同门电压下的平衡电导及电流-电压(I-V)曲线性质的影响,文中也进行了分析比较.

We investigate on the transport properties of one dimensional adulterant carbon wire coupled to two Al （100） electrodes based on a recently developed ab-initio nonequilibrium Green function formalism. The transport properties of the carbon wire with one of the carbon atom substituted by Si atom and the carbon wire with different length substituted by one of Si atom are calculated. We also study the variation of the transport properties of the carbon wire with substitution of other atom, such N, P, S. We find that the equilibrium conductance varies in an oscillatory manner for the adulterant carbon wire and the even-odd behavior also exists with the different substitution site. The variation of the transmission spenctra, the current - voltage character and the conductance under different gate-voltage for the adulterant carbon wire are also analvzed.