Influence of linear-energy-dependent density of states on two-band superconductors: Three-square-well model approach

We have derived the expressions for the transition temperature and the isotope effect exponent within the framework of Bogoliubov–Valatin two-band formalism using a linear-energy-dependent electronic density of states assuming a three-square-well potentials model. Our results show that the approach could be used to account for a wide range of values of the transition temperature and isotope effect exponent. The relevance of the present calculations to MgB2 is analyzed.

► We derived the transition temperature and the isotope exponent of two-band superconductor. ► We employed Bogoliubov–Valatin formalism assuming a three-square-well potential. ► The effect of linear-energy-dependent electronic DOS in superconductors is considered. ► The relevance of the studies to MgB2 is analyzed.