中文摘要：

基于局域原子轨道的密度泛函理论和非平衡格林函数方法,研究了碳链输运特性对分别吸附7种常见官能团NO2,CN,CHO,Br,C6H5,C5H4N和NH2时的敏感性.计算表明,电流对C6H5和CHO的吸附最为敏感,其次是对CN和C5H4N的吸附,在某些偏压下电流有大幅度的下降,其值仅为未吸附官能团体系的1/2,甚至接近1/3.对于吸附官能团为NO2,NH2及Br时,电流变化较小.这种边基对输运的影响是由于基团的吸附使本征通道被强烈抑制、碳链上布居数改变、最高已占分子轨道及最低未占分子轨道的离域性降低以及共振分子轨道的改变所造成.

英文摘要：

Based on the local atomic-orbital density functional theory plus the nonequilibrium Green’s function approach,we study the transport sensitivities of a carbon atomic wire attached,respectively with seven kinds of commonly seen side-groups NO2,CN,CHO,Br,C6H5,C5H4N,NH2. The calculated results show that the transport current is most sensitive to attached C6H5 and CHO groups,less sensitive to attached CN and C5H4N groups. Under certain bias values,the currents have a substantial decline and would reached to 1 /2,or even 1 /3 the magnitude as the unattached system C6. But the transport of the carbon atomic wire is little influenced by the attached NO2,NH2,and Br. The intrinsic origins of side-group effects on the transport current in the wire are the suppression of the transmission eigen-channel,change of the Mulliken population,diminution of the delocalization of highest occupied molecular orbital or lowest unoccupied molecular orbital,and alteration of the resonant molecular orbital.