Lambert Colin J, Liu Shi-Xia
Quantum Technology Centre, Physics Department, Lancaster University, Lancaster, LA1 4YB, UK.
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland.
Chemistry. 2018 Mar 20;24(17):4193-4201. doi: 10.1002/chem.201704488. Epub 2018 Jan 4.
This Concept article will give a glimpse into chemical design principles for exploiting quantum interference (QI) effects in molecular-scale devices. Direct observation of room temperature QI in single-molecule junctions has stimulated growing interest in fabrication of tailor-made molecular electronic devices. Herein, we outline a new conceptual advance in the scientific understanding and technological know-how necessary to control QI effects in single molecules by chemical modification. We start by discussing QI from a chemical viewpoint and then describe a new magic ratio rule (MRR), which captures a minimal description of connectivity-driven charge transport and provides a useful starting point for chemists to design appropriate molecules for molecular electronics with desired functions. The MRR predicts conductance ratios, which are solely determined by QI within the core of polycyclic aromatic hydrocarbons (PAHs). The manifestations of QI and related quantum circuit rules for materials discovery are direct consequences of the key concepts of weak coupling, locality, connectivity, mid-gap transport and phase coherence in single-molecule junctions.
这篇概念文章将简要介绍在分子尺度器件中利用量子干涉（QI）效应的化学设计原则。在单分子结中对室温量子干涉的直接观测激发了人们对制造定制分子电子器件的日益浓厚的兴趣。在此，我们概述了通过化学修饰控制单分子中量子干涉效应所需的科学理解和技术诀窍方面的一项新的概念进展。我们首先从化学角度讨论量子干涉，然后描述一种新的神奇比率规则（MRR），它捕捉了连接性驱动的电荷传输的最小描述，并为化学家设计具有所需功能的分子电子学合适分子提供了一个有用的起点。神奇比率规则预测的电导比率仅由多环芳烃（PAHs）核心内的量子干涉决定。量子干涉的表现以及用于材料发现的相关量子电路规则是单分子结中弱耦合、局域性、连接性、带隙中传输和相位相干等关键概念的直接结果。
