Probing the electron-phonon coupling in MgB2 through magnetoresistance measurements in neutron irradiated thin films

We report magnetoresistance (MR) measurements on MgB2 and the corresponding full account from ab initio calculations; we suggest that this combination can be a useful tool to probe electron-phonon coupling. We obtain good quantitative agreement between high-field measurements on neutron-irradiated epitaxial thin films and calculations within Bloch-Boltzmann transport theory over a wide range of magnetic fields (0–28 T) and temperatures (40–300 K), and as a function of the field orientation. The crossovers between in-plane and out-of-plane MR, experimentally observed as a function of either disorder or temperature are well reproduced indicating that disorder and interaction with phonons strongly affect the scattering rate of σ-carriers.