Superconductivity and Normal State In‐Plane Resistivity of MgB2: Screened Optical Phonon Approach

It is intended to trace the evolution of an effective two‐dimensional dynamic interaction with s wave pairing embodying the screening of holes as carriers (σ band) by charge density fluctuations and by optical phonons leading to superconductivity in high‐Tc MgB2. Within the developed effective interaction potential the Tc of MgB2 for σ (π) band electrons is estimated as 42 (19) K. The pressure derivative of Tc yields a negative value. Temperature dependence of resistivity of MgB2 is then theoretically analyzed within the framework of electron‐phonon i.e., Bloch‐Gruneisen model. The estimated contribution to resistivity, when subtracted from single crystal data implies a quadratic temperature dependence over most of the temperature range.