Scanning tunneling microscopy study of superconducting vortices in atomic-layer indium
Superconducting atomic-layer materials provide us an opportunity to observe phenomena that cannot be found in bulk materials. For example, the superconducting properties are expected to be modified by controlling surface defects or by covering it with molecular overlayers. Recently we have studied the role of surface atomic steps on the superconductivity of atomic-layer indium on Si(111) by using low-temperature scanning tunneling microscopy . The anomalous superconducting vortices observed at the atomic steps indicate that the atomic steps work as Josephson junctions limiting the flow of supercurrents.
 S. Yoshizawa, H. Kim, T. Kawakami, Y. Nagai, T. Nakayama, X. Hu, Y. Hasegawa, and T. Uchihashi: Phys. Rev. Lett. 113, 247004 (2014).