PHYSICS/BK21 SEMINAR (08/08/26)

"제목: Persistent superconductivity and its Interplay with quantum size      
        effects in ultrathin Pb films: An STM/S study
  
연사: Dr. Daejin Eom[Columbia University]

일시: 2008 년 8 월 26 일 14:00-15:00
장소: 물리학과 세미나실(3-201)

ABSTRACT:

Thin film superconductivity is a subject of great scientific and technological importance. There are a few intriguing aspects for 2D superconductivity. One of them is the existence of a superconductor-insulator transition in thin films with disorder. Another aspect is the possible influence of quantum confinement of single particle states upon the collective electronic phenomenon of superconductivity. In this talk, I will address a direct probe of the superconducting gap of epitaxially grown crystalline Pb films in the ultrathin regime (5-18 ML) by using scanning tunneling microscopy/spectroscopy (STM/S). The 2D Cooper pair condensate turns out to remain extremely robust down to the thinnest film (5 ML) without any signature of suppression. Also, very persistent quantum oscillations of superconductivity as a function of thickness are observed even in this ultrathin regime. This oscillation correlates directly with the density of states (DOS) oscillation at the Fermi level.

문의처: 이기봉(054-279-2068, kibong@postech.ac.kr)
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