Effect of interband interaction on isotope effect exponent of MgB 2 superconductors

Abstract

The exact formula of Tc's equation and the isotope effect exponent of two-band s-wave superconductors in the weak-coupling limit are derived by considering the influence of interband interaction. In each band, our model consists of two pairing interactions: The electron-phonon interaction and non-electron-phonon interaction. We find that the isotope effect exponent of MgB2, α = 0.3 with Tc ≈ 40 K can be found in the weak coupling regime and interband interaction of electron-phonon shows more effect on the isotope effect exponent than on the interband interaction of non-phonon. © Indian Academy of Sciences.