Scanning tunneling spectroscopy on low- and high-T c superconductors

Abstract

Articles you may be interested inStudies of low coverage adsorption of Li on Si(001): Observation of negative differential resistance and electron trapping J.Using some sophisticated modes of scanning tunneling spectroscopy the local density of states on two superconducting compounds in the superconductive state at 4.2 K were analyzed. On NbSe 2 which is a type-II low-T c material, the Abrikosov flux line lattice was imaged for various external magnetic fields up to B C2 . The field-induced decrease of the vortex core radius for increasing magnetic field, which was recently predicted by a microscopic theory, could be clearly verified. On sputtered YBa 2 Cu 3 O 7Ϫ␦ films the measurements yielded some distinct types of the surface density of states involving gaps, being in accordance to the Bardeen-Cooper-Schrieffer theory, unexpectedly large gaps, Coulomb staircases, and zero-bias peaks.