Local study of disordered superconductors

• Applicant: Dr. Idan Tamir, Ph.D.
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2021 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 455359968

The proposed study centers on disordered superconductors. Although superconductivity is insensitive to enormous amounts of disorder, many times an unexpected granular electronic structure can develop in such systems exhibiting a spatially varying superconducting gap. More recently it was reported that, upon further increase of disorder, a second, collective, gap can also develop in disordered films. Following these results we initiated a comparative local spectroscopy study of several thin-film superconductors. Our initial results suggest the existence of an underlying order governing the superconducting phase in low-disordered films. We also found unforeseen in-gap excitations already in these low-disorder films. We propose to study the emergent order and different in-gap states as a function of disorder level and film thickness. Our great advantage stems from increased resolution using superconducting tips, and access to a variety of different films allowing us to study common physical properties of disordered superconductors rather than focusing on sample dependent details.

• DFG Programme: WBP Position