2021 年 64 巻 9 号 p. 406-410
For realizing single molecular devices using metal-molecule-metal junction, it is necessary to fabricate a steady conductive bridge-structure. Recently, our group reported a molecular bridging method using migration of gold atoms on static nanogap electrodes. It was proposed that repeated cycles of single-molecular-bridging and breaking between benzene-di-thiolate (BDT) molecules and nanogap electrodes using this method. In this paper, to confirm the bridging condition during the cycles, current-voltage curves in each state were investigated. This result indicates that characteristic orbital energies of BDT were revealed while observed conductance was close with 11.0 mG0. On the other hand, when the observed conductance was below 11.0 mG0, the magnitude of estimated orbital energies was the similar as that using nanogap electrodes which were not covered by any molecules, which explained that direct tunneling conduction between Au electrodes was dominant. This clearly indicates that cycles between molecular-bridging and disconnection were realized using static nanogap structures.