Effect of interband interaction on isotope effect exponent of MgB2 superconductors

Abstract

The exact formula of T c 's equation and the isotope effect exponent of twoband s-wave superconductors in weak-coupling limit are derived by considering the influence of interband interaction . The paring interaction in each band consisted of 2 parts : the electron-phonon interaction and non-electron-phonon interaction are included in our model. The isotope effect exponent of MgB 2 , 3 . 0 = α with 40 T c ≈ K ,can be found in the weak coupling regime and interband interaction of electron-phonon interaction show more effect on isotope effect exponent than of nonphonon interaction .