Determination of the energy gap in a thin YBa2Cu3O7−x film by Andreev reflection and by tunneling
| Autor: | D. van der Marel, L.E.C. Van De Leemput, P.J.M. van Bentum, H. van Kempen, A.J.G. Schellingerhout, H.F.C. Hoevers |
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| Rok vydání: | 1988 |
| Předmět: |
Superconductivity
Materials science Yield (engineering) Condensed matter physics Band gap Energy Engineering and Power Technology Condensed Matter Physics Lower limit Electronic Optical and Magnetic Materials Andreev reflection Reflection (mathematics) Electrical and Electronic Engineering Thin film Quantum tunnelling |
| Zdroj: | Physica C: Superconductivity. 152:105-110 |
| ISSN: | 0921-4534 |
| DOI: | 10.1016/0921-4534(88)90078-0 |
| Popis: | We have observed for the first time Andreev reflection at the normal metal-superconductor interface in a thin film Ag-YBa 2 Cu 3 O 7− x sample, which indicates a zero-momentum paired state in this high- T c superconductor. The energy-dependence of the reflection probability indicates a lower limit of the energy gap in the YBa 2 Cu 3 O 7− x equal to Δ = 12.5±2 meV. Tunneling measurements on the same thin-film samples are in reasonable agreement with this value and yield Δ = 14±2 meV. Both results are not incompatible with the weak-coupling BCS prediction 2 Δ / k B T c = 3.5. |
| Databáze: | OpenAIRE |
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