Ab initio electron-defect interactions using Wannier functions

TL;DR

This paper introduces a Wannier function-based interpolation scheme that enables efficient and accurate first-principles calculations of electron-defect interactions, significantly advancing the study of charge carrier dynamics in defective materials.

Contribution

The authors develop a novel Wannier function interpolation method to compute electron-defect interactions efficiently from first principles, overcoming previous computational limitations.

Findings

Accurately reproduces direct calculations of e-d matrix elements

Speeds up calculations of relaxation times and resistivity

Demonstrates application to vacancy defects in silicon and copper

Abstract

Computing electron-defect (e-d) interactions from first principles has remained impractical due to computational cost. Here we develop an interpolation scheme based on maximally localized Wannier functions (WFs) to efficiently compute e-d interaction matrix elements. The interpolated matrix elements can accurately reproduce those computed directly without interpolation, and the approach can significantly speed up calculations of e-d relaxation times and defect-limited charge transport. We show example calculations of vacancy defects in silicon and copper, for which we compute the e-d relaxation times on fine uniform and random Brillouin zone grids (and for copper, directly on the Fermi surface) as well as the defect-limited resistivity at low temperature. Our interpolation approach opens doors for atomistic calculations of charge carrier dynamics in the presence of defects.