English

Electron-Phonon or Hole Superconductivity in $MgB_2$?

Superconductivity 2009-11-07 v2 Strongly Correlated Electrons

Abstract

The BCS electron-phonon mechanism and the unconventional 'hole mechanism' have been proposed as explanations for the high temperature superconductivity observed in MgB2MgB_2. It is proposed that a critical test of which theory is correct is the dependence of TcT_c on hole doping: the hole mechanism predicts that TcT_c will drop rapidly to zero as holes are added, while the electron-phonon mechanism appears to predict increasing TcT_c for a substantial range of hole doping. Furthermore, the hole mechanism and electron-phonon mechanism differ qualitatively in their predictions of the effect on TcT_c of change in the BBB-B distances. We discuss predictions of the hole mechanism for a variety of observables as a function of doping, emphasizing the expected differences and similarities with the electron-phonon explanation. The hole mechanism predicts coherence length and penetration depth to increase and decrease monotonically with hole doping respectively.

Keywords

Cite

@article{arxiv.cond-mat/0102479,
  title  = {Electron-Phonon or Hole Superconductivity in $MgB_2$?},
  author = {J. E. Hirsch and F. Marsiglio},
  journal= {arXiv preprint arXiv:cond-mat/0102479},
  year   = {2009}
}

Comments

Minor changes in wording in view of referee's comments; one curve added to fig. 11; under consideration for publication in Phys.Rev. B

R2 v1 2026-07-22T10:17:20.517Z