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Phonon structure in point-contact spectra of MgB$_2$

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 نشر من قبل Igor Yanson
 تاريخ النشر 2004
  مجال البحث فيزياء
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 تأليف I. K. Yanson




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In strong-coupling superconductors with a short electron mean free path the self-energy effects in the superconducting order parameter play a major role in the phonon manifestation of the point-contact spectra at above-gap energies. We compare the expressions for the nonlinear conductivity of tunnel, ballistic, and diffusive point-contacts and show that these expression are similar and correspond to the measurements of the phonon structure in the point-contact spectra for the $pi$-band of MgB$_{2}$.



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In strong-coupling superconductors with a short electron mean free path the self-energy effects in the superconducting order parameter play a major role in the phonon manifestation of the point-contact spectra at the above-gap energies. We derive asy mptotic expressions of the phonon structure in MgB$%_{2}$ in the case $eVggDelta $ for tunnel, ballistic, and diffusive point-contacts and show that these expressions not only qualitatively, but also semi-quantitatively correspond to the measurements of the phonon structure in the point-contact spectra for the $pi$-band of MgB$_{2}$ c-axis oriented thin films.
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