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The superconducting gap of \QTR{em}{in situ} $MgB_{2}$ thin films by microwave surface impedance measurements

N. Hakim·C. Kusko·S. Sridhar·A. Soukiassian·X. H. Zeng·X. X. Xi·.
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Abstract

Precision measurements of the microwave surface resistance $R_{s}$ of in situ $MgB_{2}$ films directly reveal an exponential behavior of $R_{s}$ at low temperature indicating a fully-gapped order parameter. The entire temperature dependence of $R_{s}$ is well described by a Mattis-Bardeen formalism but with a small gap ratio of $Δ(0)/kT_{c}=0.72$, corresponding to $Δ(0)=1.9meV$.

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N. Hakim, C. Kusko, S. Sridhar, A. Soukiassian, X. H. Zeng, X. X. Xi, .. 2002-12-01. The superconducting gap of \QTR{em}{in situ} $MgB_{2}$ thin films by microwave surface impedance measurements. https://doi.org/10.1063/1.1517181

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