Dresden 2020 – scientific programme
The DPG Spring Meeting in Dresden had to be cancelled! Read more ...
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 16: Poster Session Superconductivity, Cryogenic Particle Detectors, Cryotechnique
TT 16.3: Poster
Monday, March 16, 2020, 15:00–19:00, P2/EG
Scanning tunneling spectroscopy on disordered superconductors — •Martina Trahms1, Idan Tamir1, Franzisca Gorniaczyk2, Marc Westig1, Karl Jacobs3, Dan Shahar2, and Katharina J. Franke1 — 1Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany. — 2Department of Condensed Matter Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel. — 3I. Physikalisches Institut, Universität zu Köln, 50937 Köln, Germany.
In some materials superconductivity co-exists with a certain amount of disorder. The true microscopic nature of disordered superconductors remains unknown [1]. These systems have mainly been investigated in transport experiments which average over the macroscopic sample area. More recently, scanning tunneling microscopy/spectroscopy (STM/STS) measurements revealed large spatial fluctuations of the superconducting gap, indicating a local modification of the ground-state [2]. Here, we will present preliminary results of high resolution STM measurements enabled by utilizing superconducting tips. We study thin films of amorphous InO and polycrystalline NbN as well as a 400 nm TiN sample. We observe local gap variations on the nanometer length scale and resolve a number of in-gap states showing high fluctuations both in energy and spatial distribution.
[1] P. W. Anderson, J. Phys. Chem. Solids 11, 26-30 (1959).
[2] B. Sacépé et al., Phys. Rev. Lett. 101, 157006 (2008).