| AVS 58th Annual International Symposium and Exhibition | |
| Nanometer-scale Science and Technology Division | Tuesday Sessions |
| Session NS+AS-TuA |
| Session: | Frontiers in Nanoscale Imaging and Characterization |
| Presenter: | Sangjun Jeon, Seoul National University, Republic of Korea |
| Authors: | S. Jeon, Seoul National University, Republic of Korea H. Suh, Samsung Advanced Institute of Technology, Republic of Korea Y. Oh, Seoul National University, Republic of Korea S. Kim, Seoul National University, Republic of Korea Y. Kuk, Seoul National University, Republic of Korea M. Machida, Japan Atomic Energy Agency, Japan |
| Correspondent: | Click to Email |
Despite successful macroscopic picture on a conventional superconductor niobium(Nb), not much were reported on nanometer scale objects. One may have to consider quantum mechanical size effect, fluctuation, and quantum phase slip in a nanometer scale superconducting object. In this study, quantum size effect of superconducting niobium(Nb) nano-islands grown on a tungsten(W) surface was investigated with scanning tunneling microscopy(STM) and scanning tunneling spectroscopy(STS). Various size (30nm ~ 200nm) of niobium islands were formed on a W(110) surface after making several layers of wetting layer. STS measurement at 4.2K showed that the Nb island have a BCS-like superconducting gap of about 2meV around the Fermi level. The critical temperature is much lower than that of the bulk value. In addition, We found spatial dispersion of DOS (density of states) outside of the superconducting gap. Spatially-resolved scanning tunneling spectroscopy(SR-STS) data taken inside and outside of the niobium islands reveal unique dispersion. That can be understood by quantum size effect based on Bogoliubov - de Gennes equation.