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Superconducting energy gap distribution of MgB$_2$ investigated by point-contact spectroscopy

F. Laube·G. Goll·J. Hagel·H. v. Löhneysen·D. Ernst·T. Wolf
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Abstract

We performed point-contact spectroscopy on the binary superconductor MgB$_2$. The differential conductance shows gap-related structures which vary in width and position from contact to contact. The distribution of energy gaps shows a distinct accumulation around 1.7 and 7 meV which is associated with the occurrence of a small and a large energy gap in MgB$_2$. While with increasing $T$ the structure in $dI/dV$ associated with the small gap is present up to $T_C$, in magnetic field it is suppressed well below $B_{c2}$.

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F. Laube, G. Goll, J. Hagel, H. v. Löhneysen, D. Ernst, T. Wolf. 2001-06-20. Superconducting energy gap distribution of MgB$_2$ investigated by point-contact spectroscopy. https://doi.org/10.1209/epl%2Fi2001-00519-4

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