Spatial variation of superconducting gap: Stm measurements for nbn

Abstract

A low temperature scanning tunneling microscope [1] was used to study the relationship between NbN film properties and topographic structure by simultaneously measuring the surface topography and the spatial variation of the superconducting energy gap. The images show significant variation of the energy gap with position. Regions with no superconducting energy gap arise when magnetic fields of 6 Tesla are applied and some evidence of a correlation between the surface and energy gap topography appears. © 1987 The Japan Society of Applied Physics.