Evidence of two-gap s-wave superconductivity in from microwave surface impedance measurements
- 15 November 1993
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 71 (20), 3355-3358
- https://doi.org/10.1103/physrevlett.71.3355
Abstract
Epitaxial thin films of with low cation and oxygen disorder exhibit two features in the temperature dependence of the microwave surface impedence which are consistent with a weak s-wave superconducting state associated with the CuO chains. First, both the microwave surface resistance and the magnetic field penetration depth exhibit a weak exponential temperature dependence below 30 K corresponding to an energy gap of about 6 meV. Second, the penetration depth exhibits a small bump at about 60 K, which is consistent with a two-band BCS calculation using 6 meV for the smaller gap.
Keywords
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