烯链分子线导电过程中的长度依赖

Length-Dependent of the Electron Transportation in Alkenedithiol Chains

在密度泛函理论与格林函数方法的基础之上,研究了烯链分子线的导电能力随着分子长度的变化规律。通过改变烯链分子线与电极之间的耦合强度得到了烯链的导电能力的长度依赖可以是指数衰减、震荡衰减、多项式衰减等。因此指数衰减并不是刻画分子线导电的唯一规律,衰减指数也不是刻画分子线的唯一标准;震荡衰减也可以在分子线中存在。这对未来分子导线的设计具有重要的意义。

Based on Density Functional Theory （DFT） and Green Functional （GF） method, we studied the conductance properties of alkenedithiol chains with the changing of molecular length. Through the controlling of the coupling strength between molecular wire and electrodes, we get the exponential decay, the oscillatory deeay, and the polynomial decay. The exponential decay is not the only law which characterized the eonduetance properties of molecular wire and the damping factor is not the only value which defined the molecular wire. The oscillatory decay can exist in molecular wire and not only in atom wire.