中文摘要：

该文采用基于密度泛函理论的非平衡格林函数方法研究了非对称分子HOOC-C6H4-（CH2）2的输运特性.非对称分子HOOC-C6H4-（CH2）2放在具有有限截面的Al（100）电极中.研究发现,非对称分子HOOC-C6H4-（CH2）2中存在很好的电流开关现象：随着外加偏压的升高,通过分子的电流迅速增加;但是当偏压升高到0.6 V之后,电流开始减少;在1.3 V时,电流几乎处于截止状态.得到了很高的开关流系数~40,非对称分子HOOC-C6H4-（CH2）2的这种导电特性将能在未来的分子器件中有着非常重要的应用.通过分析各种偏压下的透射谱图,阐述了分子开关产生的原因.

英文摘要：

We investigate the transport properties of an asymmetric molecule HOOC-C6H4-（CH2）2 coupled to two AI（100） electrodes based on a recently developed density functional theory and non-equilibrium Green function formalism. Our resuit shows that there exists a good switch in the asymmetric molecule HOOC-C6H4-（CH2）2. The current increases quickly with the increase of the applied bias in the bias range of 0 - 0.6 V, but the current begins to decrease when the bias over 0.6 V and it is depressed enormously around the applied bias of 1.3 V. A switch ratio of - 40 is gained which has potential applications in future molecular devices. In addition, an explanation for the reason of molecular switch is given.