Postdoctoral Researcher Hongliang Chen’s research article entitled Promotion and Suppression of Single-molecule Conductance by Quantum Interference in Macrocyclic Circuits has been published in Matter.
Single-molecule electronics is a sub-field of nanoelectronics in which the 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 the source to the drain. Their future development, however, is hampered by difficulties in controlling such interference effects. For example, the conductance of a ring-shaped single-molecule macrocyclic circuit can be manipulated through the quantum interference (QI) between de Broglie waves of electrons traversing two branches of the loop structure, leading to conductance enhancement in the presence of constructive quantum interference (CQI) and conductance suppression when destructive quantum interference (DQI) occurs.
Hongliang and colleagues show both theoretically and experimentally that, such a QI control strategy is realized by introducing energy and phase shifts into the de Broglie waves of electrons traversing different conducting channels of cyclophanes. In positively charged tetracationic cyclophanes, by making the electron transport through each channel LUMO-dominated, the switching between CQI and DQI can be simply manipulated by changing one of the two conducting channels. Energy differences between these two LUMO channels induce CQI, leading to high conductance. By contrast, phase differences between these LUMO channels result in DQI and a suppression in the overall conductance. Such a design of single-molecule circuits enables the construction of single-molecule conductors and insulators based on a single cyclophane platform.
Congratulations Hongliang! Nice Work!
H. Chen, H. Zheng, C. Hu, K. Cai, Y. Jiao, L. Zhang, F. Jiang, I. Roy, Y. Qiu, D. Shen, Y. Feng, F. M. Alsubaie, H. Guo, W. Hong, J. F. Stoddart, Giant Conductance Enhancement of Intramolecular Circuits through Interchannel Gating, Matter 2020, 2, 378. DOI: 10.1016/j.matt.2019.12.015.
H. Chen, S. Hou, Q. Wu, F. Jiang, P. Zhou, L. Zhang, Y. Jiao, B. Song, Q.-H. Guo, X.-Y. Chen, W. Hong, C. J. Lambert, J. F. Stoddart, Promotion and suppression of single-molecule conductance by quantum interference in macrocyclic circuits, Matter 2021, 4, 3662. DOI: 10.1016/j.matt.2021.08.016.
Pictured below – Top: Hongliang Chen alongside the Graphical Abstract for his research article in Matter. Bottom: Schematic illustration showing the design of molecular conductors (Matter 2020, 2, 378), molecular insulators (Matter 2021, 4, 3662), and molecular integrated circuits (Future Work).