量子干涉（QI）在相位相干长度范围内的分子器件的工作中起着至关重要的作用，而利用QI的模式，即构造干涉和相消干涉是至关重要的。然而，与大多数栅电极相比，单分子器件的尺寸太小。这些门的作用就像一个后门，均匀地影响分子组分。在相同分子骨架中转换量子干涉的模式仍然具有挑战性。
该文中，研究人员开发了原子精确的门控策略，控制分子组分的前线轨道，实现了破坏性的QI模式与构造性的QI模式之间的完全转换，并在室温下导致显著的电导调制。通过与阳离子试剂的选择性相互作用，在吡啶氮上局部施加化学门控效应，并根据需要控制开关可逆性。
研究人员展示了原子精确门控在单分子尺度上调制量子干涉的独特效果，为开发新概念电子器件开辟了一条途径。
附：英文原文
Title: Reversible Switching between Destructive and Constructive Quantum Interference Using Atomically Precise Chemical Gating of Single-Molecule Junctions
Author: Chun Tang, Longfeng Huang, Sara Sangtarash, Mohammed Noori, Hatef Sadeghi, Haiping Xia, Wenjing Hong
Issue&Volume: June 18, 2021
Abstract: Quantum interference (QI) plays an imperative role in the operation of molecular devices within the phase-coherent length, and it is vital to harness the patterns of QI, i.e., constructive and destructive interference. However, the size of the single-molecule device is too small compared to most gate electrodes. Those gates act like a backgate to affect the molecular component uniformly. Switching the patterns of QI in the same molecular skeleton remains challenging. Here, we develop the atomically precise gating strategy that manipulates the frontier orbitals of molecular components, achieving the complete switching of QI patterns between destructive to constructive QI and leading to a significant conductance modulation at room temperature. The chemical gating effect is exerted locally on the pyridine nitrogen through the selective interaction to cationic reagents, with which we can also control the switching reversibility as desired. We demonstrate the unique effect of atomically precise gating to modulate the quantum interference at the single-molecule scale, opening an avenue to develop new-conceptual electronic devices.
DOI: 10.1021/jacs.1c00928
Source: https://pubs.acs.org/doi/10.1021/jacs.1c00928
