arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0912.4147cond-mat.mes-hallcond-mat.mtrl-sci
收藏

通过有机分子的量子输运

Quantum Transport through Organic Molecules

Santanu K. Maiti

摘要:

利用格林函数方法研究了苯-1,4-二硫纶(BDT)分子模型和苯分子在两个半无限一维金属电极上的电子输运性质.基于一个简单的紧束缚框架,提出了一种分析方法来描述电子输运通过分子导线。在这样的分子系统中的电子输运强烈地受到分子的几何形状以及它们与侧附电极的耦合的影响。电导揭示了与分子能量本征态相关的共振峰,提供了几个复杂的光谱。通过分子的电流表现出阶梯状的行为与尖锐的步骤在弱的分子-电极耦合的限制,而它的变化相当连续与施加的偏置电压在强的分子耦合的限制。在横向磁场的存在下,电导表现出振荡行为与通量$ϕ$,通过分子环,显示$ϕ_0$($=ch/e$)通量量子周期性。虽然电导在横向磁场的存在下发生变化,但电流-电压特性不受此场的显著影响。

英文摘要:

We explore electron transport properties for the model of benzene-1, 4-dithiolate (BDT) molecule and for some other geometric models of benzene molecule attached to two semi-infinite one-dimensional metallic electrodes using the Green's function formalism. An analytic approach, based on a simple tight-binding framework, is presented to describe electron transport through the molecular wires. Electronic transport in such molecular systems is strongly affected by the geometry of the molecules as well as their coupling to the side-attached electrodes. Conductance reveals resonant peaks associated with the molecular energy eigenstates providing several complex spectra. Current passing through the molecules shows staircase-like behavior with sharp steps in the weak molecule-to-electrode coupling limit, while it varies quite continuously with the applied bias voltage in the limit of strong molecular coupling. In the presence of transverse magnetic field, conductance exhibits oscillatory behavior with flux $ϕ$, threaded by the molecular ring, showing $ϕ_0$ ($=ch/e$) flux-quantum periodicity. Though, conductance changes in the presence of transverse magnetic field, but the current-voltage characteristics are not significantly affected by this field.

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。

↑