Phonon structure in point-contact spectra of MgB$_2$
arXiv:cond-mat/0405246
Abstract
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 $Ï$-band of MgB$_{2}$.
6 pages, 6 figures. Proc. NATO Advanced Research Workshop on New Challenges in Superconductivity, January 2004, Miami, USA