Conduction mechanism of single-electron transistors fabricated by field-emission-induced electromigration

We report the conduction mechanism of the single-electron transistors (SETs) fabricated by field-emission-induced electromigration, which is so-called “activation”. By applying the activation to Ni nanogaps, we were easily able to fabricate the SETs operating at room temperature. Additionally, strong Coulomb staircases were clearly obtained, and the quasi-periodic current oscillations were also observed at room temperature. These results indicate that the higher charging energy associated with a smaller Ni island structure within the multiple islands causes a bottleneck mechanism in conduction, improving the Coulomb staircase structures.