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

TL;DR

This study combines magnetoresistance measurements and ab-initio calculations to investigate electron-phonon coupling in MgB2, revealing how disorder and phonons influence carrier scattering.

Contribution

It demonstrates that magnetoresistance measurements, supported by theoretical calculations, can effectively probe electron-phonon interactions in MgB2 thin films.

Findings

Good agreement between experiments and calculations across various conditions.

Disorder and phonons significantly impact carrier scattering rates.

Crossovers in MR behavior are well explained by the model.

Abstract

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 s-carriers.