The quantum interference effect in the charge transport through single-phenyl molecules received intensive interests from theory but remained as an experimental challenge. In this paper, we investigated the charge tra...The quantum interference effect in the charge transport through single-phenyl molecules received intensive interests from theory but remained as an experimental challenge. In this paper, we investigated the charge transport through single-molecule benzene dithiol （BDT） junction with different connectivities using mechanically controllable break.junction （MCB]） technique. By further improving the mechanical stability and the electronic measuring component of the MCBJ set-up, we obtained the conductance histograms of BDT molecules （BDTs） from the statistical analysis of conductance-distance traces without data selection. By tuning the connectivity, the conductance of BDTs is determined to be 10-12Go, 10-22Go and 10-10Go for pcra, meta, and ortho connectivity, following the trend that ortfio-BDT 〉 para-BDT 〉 meta-BDT. Furthermore, the displacements of the junctions followed the trend that para 〉 meta 〉 ortho, suggesting the charge transport through the molecules via the gold-thiol bond. The different trends between conductance and displacement for different connectivities suggests the presence of destructive quantum interference effect on meta-BDT, which provides the experimental evidence for the quantum interference effect through single-phenyl molecular junctions.展开更多
基金supported by the Ministry of Science and Technology of China(No. SQ2017YFJC020081)the National Natural Science Foundation of China(Nos. 21673195,21503179)+2 种基金Fundamental Research Funds for the Central Universities in China (Xiamen University: No. 20720170035)Natural Science Foundation of Fujian Province(No. 2016J05162)the Young Thousand Talent Project of China
文摘The quantum interference effect in the charge transport through single-phenyl molecules received intensive interests from theory but remained as an experimental challenge. In this paper, we investigated the charge transport through single-molecule benzene dithiol （BDT） junction with different connectivities using mechanically controllable break.junction （MCB]） technique. By further improving the mechanical stability and the electronic measuring component of the MCBJ set-up, we obtained the conductance histograms of BDT molecules （BDTs） from the statistical analysis of conductance-distance traces without data selection. By tuning the connectivity, the conductance of BDTs is determined to be 10-12Go, 10-22Go and 10-10Go for pcra, meta, and ortho connectivity, following the trend that ortfio-BDT 〉 para-BDT 〉 meta-BDT. Furthermore, the displacements of the junctions followed the trend that para 〉 meta 〉 ortho, suggesting the charge transport through the molecules via the gold-thiol bond. The different trends between conductance and displacement for different connectivities suggests the presence of destructive quantum interference effect on meta-BDT, which provides the experimental evidence for the quantum interference effect through single-phenyl molecular junctions.
