Vortex state in microfabricated superconducting disk probed by tunneling spectroscopy

Low-temperature STM and STS were applied to the study of superconducting ga p variations induced by perpendicular magnetic field within a microfabricat ed In disk. Abrupt changes of the gap observed at the disk center during ma gnetic field sweep are attributed to the switch between different vortex st ates. Spatial distribution of the superconducting gap defined by a magnetic flux configuration was also obtained. The results are partially in accorda nce with the distribution predicted for the giant multi-quanta vortices. (C ) 2000 Published by Elsevier Science B.V. All rights reserved.