Department of Physics, Center for Atomic-scale Materials Design (CAMD), Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
J Chem Phys. 2010 Jun 14;132(22):224104. doi: 10.1063/1.3451265.
Using first-principles calculations we analyze the electronic transport properties of a recently proposed anthraquinone-based electrochemical switch. Robust conductance on/off ratios of several orders of magnitude are observed due to destructive quantum interference present in the anthraquinone but absent in the hydroquinone molecular bridge. A simple explanation of the interference effect is achieved by transforming the frontier molecular orbitals into localized molecular orbitals thereby obtaining a minimal tight-binding model describing the transport in the relevant energy range in terms of hopping via the localized orbitals. The topology of the tight-binding model, which is dictated by the symmetries of the molecular orbitals, determines the amount of quantum interference.
利用第一性原理计算，我们分析了一种最近提出的蒽醌基电化学开关的电子输运性质。由于蒽醌中存在而在氢醌分子桥中不存在的破坏性量子干涉，观察到几个数量级的稳健电导开/关比。通过将前沿分子轨道转化为局域分子轨道，从而获得一个描述通过局域轨道跃迁的相关能量范围内的输运的最小紧束缚模型，对干涉效应进行了简单的解释。紧束缚模型的拓扑结构由分子轨道的对称性决定，决定了量子干涉的程度。
