Journal of Superconductivity

, Volume 8, Issue 4, pp 467–470 | Cite as

STM tunneling spectroscopy on high Tc superconductors

  • T. Hasegawa
  • M. Nantoh
  • M. Ogino
  • H. Sugawara
  • M. Kawasaki
  • H. Koinuma
  • K. Kitazawa
Article

Abstract

STM tunneling spectroscopy has been performed on the bulk single crystals of BiSrCaCuO (BSCCO) and the epitaxial thin films of YBaCuO (YBCO) at cryogenic temperatures. The STM images and tunneling spectra observed on the (001) surfaces can be classified into three cases; 1) Atomic image is visible. However, the tunneling spectrum shows semiconducting or smeared superconducting gap structures, depending on the tip-sample distance. 2) Clear atomic image can not be obtained. But, the tunneling spectrum shows flat bottom region with quite low zero bias conductance. 3) Tunneling spectra demonstrate gapless behavior, independent of the tip-sample separation. These observations support the quasi-2D electronic picture in whichs-wave like 2D superconducting layers are coupled with each other through the Josephson effect.

Key words

STM superconducting gap symmetry of order parameter 

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Copyright information

© Plenum Publishing Corporation 1995

Authors and Affiliations

  • T. Hasegawa
    • 1
  • M. Nantoh
    • 1
  • M. Ogino
    • 1
  • H. Sugawara
    • 1
  • M. Kawasaki
    • 2
  • H. Koinuma
    • 2
  • K. Kitazawa
    • 1
  1. 1.Department of Applied ChemistryUniversity of TokyoTokyoJapan
  2. 2.Research Laboratory of Engineering MaterialsTokyo Institute of TechnologyYokohamaJapan

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