特集「ナノスケール相転移現象の物理と化学」
単原子層超伝導における乱れと量子相転移
キーワード:
2D superconductivity,
disorder,
atomic-layer films,
scanning tunneling microscopy,
surface electron transport
2026 年 69 巻 3 号 p. 153-158
詳細
2026 年 69 巻 3 号 p. 153-158
Unlike bulk counterparts, two-dimensional (2D) superconductors are sensitive to disorder. Here, we will present enhancement of the upper critical magnetic field and reduction in critical temperature on Pb mono-atomic-layer superconductors formed on vicinal substrates, where steps work as a disorder against the 2D superconductivity. We revealed how surface steps with an interval shorter than the coherence length ξ affect the superconducting properties by scanning tunneling microscopy (STM) and surface transport measurements. STM exhibited vortices elongated along the steps, that is, Abrikosov-Josephson vortices squeezed normal to the steps due to the reduced ξ. These results demonstrate that vicinal substrates provide a unique platform to manipulate the degree of disorder on 2D superconductors.
