Temperature dependence of the superconducting proximity effect quantified by scanning tunneling spectroscopy
| Autor: | Hirofumi Oka, Dirk Sander, A. Stępniak, Jürgen Kirschner, M. Caminale, A. A. Leon Vanegas |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Superconductivity
Materials science Condensed matter physics Scanning tunneling spectroscopy General Physics and Astronomy Atmospheric temperature range lcsh:QC1-999 law.invention Tunnel effect law Condensed Matter::Superconductivity Density of states Proximity effect (superconductivity) Scanning tunneling microscope Spectroscopy lcsh:Physics |
| Zdroj: | AIP Advances, Vol 5, Iss 1, Pp 017125-017125-8 (2015) |
| ISSN: | 2158-3226 |
| Popis: | Here, we present the first systematic study on the temperature dependence of the extension of the superconducting proximity effect in a 1–2 atomic layer thin metallic film, surrounding a superconducting Pb island. Scanning tunneling microscopy/spectroscopy (STM/STS) measurements reveal the spatial variation of the local density of state on the film from 0.38 up to 1.8 K. In this temperature range the superconductivity of the island is almost unaffected and shows a constant gap of a 1.20 ± 0.03 meV. Using a superconducting Nb-tip a constant value of the proximity length of 17 ± 3 nm at 0.38 and 1.8 K is found. In contrast, experiments with a normal conductive W-tip indicate an apparent decrease of the proximity length with increasing temperature. This result is ascribed to the thermal broadening of the occupation of states of the tip, and it does not reflect an intrinsic temperature dependence of the proximity length. Our tunneling spectroscopy experiments shed fresh light on the fundamental issue of the temperature dependence of the proximity effect for atomic monolayers, where the intrinsic temperature dependence of the proximity effect is comparably weak. |
| Databáze: | OpenAIRE |
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