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Advances in point-contact spectroscopy: two-band superconductor MgB2 (A review)

I. K. Yanson·Yu. G. Naidyuk
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Abstract

Analysis of the point-contact spectroscopy (PCS) data on the new dramatic high-T$_c$ superconductor MgB$_2$ reveals quite different behavior of two disconnected $σ$ and $π$ electronic bands, deriving from their anisotropy, different dimensionality, and electron-phonon interaction. PCS allows direct registration of both the superconducting gaps and electron-phonon-interaction spectral function of the two-dimensional $σ$ and three-dimensional $π$ band, establishing correlation between the gap value and intensity of the high-T$_c$ driving force -- the $E_{2g}$ boron vibration mode. PCS data on some nonsuperconducting transition-metal diborides are surveyed for comparison.

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I. K. Yanson, Yu. G. Naidyuk. 2004-02-06. Advances in point-contact spectroscopy: two-band superconductor MgB2 (A review). https://doi.org/10.1063/1.1704612

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