The superconducting gap of \QTR{em}{in situ} $Mg{B}_2$ thin films by microwave surface impedance measurements

Abstract

Precision measurements of the microwave surface resistance $R_s$ of in situ $Mg{B}_2$ 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 $\Delta (0)/k{T}_c=0.72$, corresponding to $\Delta (0)=1.9meV$.

References in corpus (7)

• Phenomenological two-gap model for the specific heat of MgB_2
• Evidence for Two-Band Superconductivity from Break Junction Tunneling on MgB2
• Superconducting properties of nanocrystalline MgB${}_2$ thin films made by an in situ annealing process
• Anisotropic s-wave superconductivity in MgB_2
• Significant Reduction of the Microwave Surface Resistance of MgB2 Films by Surface Ion Milling
• Precision microwave dielectric and magnetic susceptibility measurements of correlated electronic materials using superconducting cavities
• Microwave properties of superconducting $Mg{B}_2$

Cited by in corpus (2)

• Study on the formation of MgB2 phase
• Effects of the Two- Gap Nature on the Microwave Conductivity of 39 K Polycrystalline MgB2 Films