title: U-shaped relationship between current and pitch in helicene molecules.
abstract: The helicene is constructed by twisted benzene or other aromatic rings, exhibiting a helical structure. Using first-principles calculations, we investigate the electronic transport of helicenes under stretching or compressing. Interestingly, a U-shaped curve of the current against d (the pitch of a helicene) is observed. Further analysis shows that, it is the result of the nonmonotonic change of HOMO-LUMO gap with d. The change of overlap between orbitals induced by conformational deformation is found to be the underlying mechanism. Moreover, the U-curve phenomenon is an intrinsic feature of the helicene molecules, being robust to the electrode materials or doping. This U-curve behavior is expected to be extended to helical graphene or other related structures, showing great application potential.
authors.affiliation: College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210046, China.|Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, Nanjing 210023, China.
authors.forename: Yan-Dong
authors.initials: YD
authors.lastname: Guo
authors.affiliation: College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210046, China.|Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, Nanjing 210023, China.|China College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Yan
authors.affiliation: China College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210046, China.|Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, Nanjing 210023, China.
authors.forename: Chun-Sheng
authors.initials: CS
authors.lastname: Liu