基于格林函数的多终端量子链状体系电子输运性质的研究

利用递推格林函数技术计算了多终端量子体系的电子输运特性，首先运用递归方法给出介观 或量子体系的格林函数. 然后利用散射矩阵和输运方程给出体系的电导方程，可以将多终端 的输运简化为双终端的输运方程，以便得到体系电子输运的谱结构. 计算结果表明，由于中 间节点的存在，使器件的传输谱偏离一维链的对称性，在低能量端出现一个新的电导峰值. 此外，本方法可以被应用到各种复杂的带有吸附结构量子体系输运的研究中. 关键词： 格林函数 散射矩阵 量子体系

Electron transport in multi-terminal quantum chain systems based on the Green's functions

We have introduced a method for the calculation of electron transport in a multi_terminal quantum system based on the recursive Green's function technique. The corresponding transport equation is presented by scattering matrix, which is expressed by Green's function. Using this method, the multi_terminal device can be simplified as a standard two_terminal device, which is convenient in treating the mesoscopic device. It is found that the transmission and reflection probabilities of the two multi_terminal quantum systems show complex spectra. The results show that the special node can destroy the symmetrical conductance spectra, and there is a new conductance peak in the low_energy region. This method can also be applied to the study of electron transport of complex mesoscopic structures.