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Point-Contact Spectroscopy in MgB_2: from Fundamental Physics to Thin-Film Characterization

R. S. Gonnelli·D. Daghero·A. Calzolari·G. A. Ummarino·V. Dellarocca·V. A. Stepanov·S. M. Kazakov·J. Karpinski·C. Portesi·E. Monticone·V. Ferrando·C. Ferdeghini
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Abstract

In this paper we highlight the advantages of using point-contact spectroscopy (PCS) in multigap superconductors like MgB_2, both as a fundamental research tool and as a non-destructive diagnostic technique for the optimization of thin-film characteristics. We first present some results of crucial fundamental interest obtained by directional PCS in MgB_2 single crystals, for example the temperature dependence of the gaps and of the critical fields and the effect of a magnetic field on the gap amplitudes. Then, we show how PCS can provide useful information about the surface properties of MgB_2 thin films (e.g. Tc, gap amplitude(s), clean or dirty-limit conditions) in view of their optimization for the fabrication of tunnel and Josephson junctions for applications in superconducting electronics.

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R. S. Gonnelli, D. Daghero, A. Calzolari, G. A. Ummarino, V. Dellarocca, V. A. Stepanov, S. M. Kazakov, J. Karpinski, C. Portesi, E. Monticone, V. Ferrando, C. Ferdeghini. 2003-09-24. Point-Contact Spectroscopy in MgB_2: from Fundamental Physics to Thin-Film Characterization. https://doi.org/10.1088/0953-2048%2F17%2F5%2F001

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