Coupled Electron-Phonon-Defect Interactions from First Principles

While ab initio methods exist for calculating electron-phonon (e-ph) and electron-defect (e-d) interactions separately, the point defects can also modify the phonons, and, consequently, e-ph interactions. A general first-principles treatment of this effect is lacking. To address this gap, we develop a method based on many-body perturbation theory (MBPT) to compute defect-modified e-ph scattering and the resulting transport properties. We extend the e-ph self-energy to include the defect-modified spectral functions of both electrons and phonons. Then using the Kubo-Greenwood formalism calculates the electrical conductivity. Our method paves a step towards intertwined physics of coupled electron-defect-phonon interactions.