<i>Ab Initio</i> Electron-Defect Interactions Using Wannier Functions

The interactions between electrons and crystallographic defects control electron scattering and transport at low temperature. Electron-defect (e-d) interactions and the associated matrix elements can be computed from first principles using density functional theory through a method we recently developed. However, relevant quantities such as the e-d relaxation times (RTs) and carrier mobility require integrals over very fine Brillouin zone grids. Since computing a large number of e-d matrix elements is expensive, convergence and accuracy at a reasonable computational cost are challenging to achieve. In this talk, we present a Wannier interpolation scheme for e-d matrix elements and apply it to example calculations of vacancy defects in semiconductors and metals. We discuss the accuracy and versatility of the interpolation scheme, which can correctly reproduce the matrix elements computed directly, and apply it to compute and systematically converge e-d RTs and defect-limited charge transport properties at low temperature. We outline how our Wannier interpolation scheme for e-d interactions can serve as a powerful ab initio tool for studying a wide range of low-temperature transport phenomena and e-d interactions in materials.