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.

中文翻译：

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使用单分子结的原子精确化学门控在破坏性和建设性量子干扰之间进行可逆切换

量子干涉 (QI) 在相位相干长度内的分子装置的运行中起着至关重要的作用，利用 QI 的模式（即相长干涉和相干干涉）至关重要。然而，与大多数栅电极相比，单分子器件的尺寸太小了。这些门就像一个后门一样均匀地影响分子成分。在同一分子骨架中切换 QI 的模式仍然具有挑战性。在这里，我们开发了原子级精确的门控策略，可以操纵分子组分的前沿轨道，实现 QI 模式在破坏性 QI 和建设性 QI 之间的完全切换，并在室温下实现显着的电导调制。通过与阳离子试剂的选择性相互作用，化学门控效应局部施加在吡啶氮上，我们还可以根据需要控制转换可逆性。我们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，为开发新概念电子设备开辟了道路。