arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1002.1398cond-mat.mes-hallcond-mat.mtrl-sci
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局域势场作用下分子结中的电流整流

Current rectification in molecular junctions produced by local potential fields

Tomasz Kostyrko, Víctor M. García-Suárez, Colin J. Lambert, Bogdan R. Bułka

摘要:

采用密度泛函理论和非平衡格林函数方法研究了辛二硫醇(ODT)分子与Au(001)引线耦合的输运性质.研究表明,在外加带电探针产生的局部电场的作用下,对称分子可以变成二极管。电流-电压($I-V$)依赖性的不对称性的起源追溯到探针诱导的准局域态的ODT分子的赝隙的外观。诱导态影响电子输运,只要它接近于引线的费米能级。带电探针沿烷烃链的非对称放置使得能隙中的感生准局域态对偏置电压非常敏感,并导致电流的整流。基于DFT的结果支持独立的计算,使用一个简单的单粒子模型哈密顿量。

英文摘要:

The transport properties of a octane-dithiol (ODT) molecule coupled to Au(001) leads are analyzed using density functional theory and non-equilibrium Green functions. It is shown that a symmetric molecule can turn into a diode under influence of a local electric field created by an external charged probe. The origin of the asymmetry of the current--voltage ($I-V$) dependence is traced back to the appearance of a probe induced quasi--local state in the pseudogap of the ODT molecule. The induced state affects electron transport, provided it is close to the Fermi level of the leads. An asymmetric placement of the charged probe along the alkane chain makes the induced quasi--local state in the energy gap very sensitive to the bias voltage and results in rectification of the current. The results based on DFT are supported by independent calculations using a simple one--particle model Hamiltonian.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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