Promotion and suppression of single-molecule conductance by quantum interference in macrocyclic circuits
Promotion and suppression of single-molecule conductance by quantum interference in macrocyclic circuits
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DOI：
10.1016/j.matt.2021.08.016
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发表时间：
2021-11-03
期刊：
影响因子：
18.9
通讯作者：
Stoddart, J. Fraser
中科院分区：
文献类型：
--
作者：
Chen, Honglian;Hou, Songjun;Stoddart, J. Fraser
单分子电子学是纳米电子学的一个子领域，其中单个器件由放置在源极和漏极之间的单分子形成。在过去的几年里，科学家们已经证明，通过这些设备的电流是由从源极到漏极的电子之间的量子干涉（QI）控制的。然而，它们的未来发展受到难以控制干扰效应的阻碍。在这里，我们证明，在四阳离子环番电路的电子传输介导的通道之间的QI形成从两个最低未占分子轨道（LUMO），而他们的最高占据分子轨道（HOMO）发挥没有显着的作用。这两个LUMO通道之间的能量差诱导相长干涉，导致高电导。相比之下，这些LUMO通道之间的相位差导致相消干涉和总体电导的抑制。单分子电路的这种设计使得能够基于单个环蕃平台构建单分子导体和绝缘体。
Single-molecule electronics is a sub-field of nanoelectronics in which individual devices are formed from single molecules placed between source and drain electrodes. During the past few years, scientists have demonstrated that the flow of electricity through these devices is controlled by quantum interference (QI) between electrons passing from source to drain. Their future development, however, is hampered by difficulties in controlling interference effects. Herein, we demonstrate that electron transport in tetracationic cyclophane circuits is mediated by QI between channels formed from two lowest unoccupied molecular orbitals (LUMOs), while their highest occupied molecular orbitals (HOMOs) play no significant role. Energy differences between these two LUMO channels induce constructive interference, leading to high conductance. By contrast, phase differences between these LUMO channels result in destructive interference and a suppression in overall conductance. Such a design of single-molecule circuits enables the construction of single-molecule conductors and insulators based on a single cyclophane platform.