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arXiv · 1006.3124

A second superconducting energy gap of Nb_3Sn observed by breakjunction point-contact spectroscopy

M. Marz·W. Goldacker·R. Lortz·G. Goll
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Abstract

We report on investigations of the superconducting energy gap of the A15 superconductor Nb_3Sn by point-contact spectroscopy of breakjunctions. The voltage-dependent differential conductance dI/dV reveals features of a second energy gap besides the energy gap known from previous tunnel measurements with maxima at \Delta_1=3.92 +/- 0.16 meV and \Delta_2=0.85 +/- 0.17 meV as derived from a histogram summarizing the data of more than 60 contacts. These findings are the first spectroscopic evidence that Nb_3Sn belongs to the class of two-band superconductors and they are in line with low-temperature specific-heat measurements on Nb_3Sn.

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M. Marz, W. Goldacker, R. Lortz, G. Goll. 2010-06-16. A second superconducting energy gap of Nb_3Sn observed by breakjunction point-contact spectroscopy. https://doi.org/10.1103/physrevb.82.024507

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