Abstract
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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3662-3676 |
| Number of pages | 15 |
| Journal | Matter |
| Volume | 4 |
| Issue number | 11 |
| DOIs | |
| State | Published - Nov 3 2021 |
Funding
The authors thank Northwestern University (NU) for its continued support of this research. The authors also acknowledge the Integrated Molecular Structure Education and Research Center (IMSERC) at NU for providing access to equipment for the experiments. The research work in Xiamen University was supported by the National Key R&D Program of China (2017YFA0204902) and the National Natural Science Foundation of China (grants 21673195 and 21722305). Computational investigations were supported by the United Kingdom Engineering and Physical Sciences Research Council (EPSRC) through grant nos. EP/N017188/1, EP/M014452/1, EP/P027156/1, and EP/N03337X/1. Support from the European Commission, European Union, was provided by the FET Open Project 767187 (QuIET) and the EU project BAC-TO-FUEL. H.C. and J.F.S. conceived the idea and designed the experiments. H.C. and S.H. wrote the manuscript with input from all authors. H.C. performed most of the experiments, including syntheses, characterizations, measurements, and data analyses. H.C. F.J. and P.Z. carried out the break junction experiments. L.Z. Y.J. and B.S. assisted with synthesis and characterization of cyclophanes. S.H. Q.W. and C.J.L. developed the underlying theoretical concepts, including the idea of using double and triple bonds to tune the QI between the two branches. H.C. W.H. C.J.L. and J.F.S. co-supervised the project. All authors contributed to and commented on the contents of manuscript. The authors declare no competing interests. The authors thank Northwestern University (NU) for its continued support of this research. The authors also acknowledge the Integrated Molecular Structure Education and Research Center (IMSERC) at NU for providing access to equipment for the experiments. The research work in Xiamen University was supported by the National Key R&D Program of China ( 2017YFA0204902 ) and the National Natural Science Foundation of China (grants 21673195 and 21722305 ). Computational investigations were supported by the United Kingdom Engineering and Physical Sciences Research Council (EPSRC) through grant nos. EP/N017188/1 , EP/M014452/1 , EP/P027156/1 , and EP/N03337X/1 . Support from the European Commission , European Union , was provided by the FET Open Project 767187 ( QuIET ) and the EU project BAC-TO-FUEL.
Keywords
- LUMO-dominated transport
- MAP3: Understanding
- STM-BJs
- cyclophanes
- intramolecular circuits
- molecular electronics
- quantum interference
- single-supermolecule electronics
ASJC Scopus subject areas
- General Materials Science