Ab initio electron-defect interactions using Wannier functions

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.

Perturbo: A software package for ab initio electron–phonon interactions, charge transport and ultrafast dynamics

“…In the iterative algorithm, we choose in the first step F 0 nk = τ nk v nk , and then compute the following steps using Eq. (10) until the difference |F i+1 nk − F i nk | is within the convergence threshold.…”

“…(8) and 13, respectively, and the iterative BTE solution in Eq. (10). In Perturbo, we adopt different BZ sampling and integration approaches for different kinds of calculations.…”

“…It can also simulate the ultrafast nonequilibrium electron dynam-ics in the presence of e-ph interactions. The developer branch, which is not publicly available yet, also includes routines for computing spin [8], electron-defect [9,10], and electron-photon interactions [11], as well as advanced methods to compute the ultrafast dynamics of electrons and phonons in the presence of electric and magnetic fields. These additional features will be made available in future releases.…”

Atomistic T -matrix theory of disordered two-dimensional materials: Bound states, spectral properties, quasiparticle scattering, and transport

“…It should be noted that the LCAO procedure for the calculation of the defect matrix elements outlined here, bears close resemblance to methods based on Wannier functions. 45,53 However, the use of a fixed LCAO basis has the advantage that the additional step for the generation of the Wannier functions, which is not always trivial, is avoided.…”

“…The first-principles T -matrix method introduced in the present work is therefore of high relevance for the further development of first-principles transport methodologies with high predictive power. [40][41][42][43][44][45] The details of our method which is implemented in the GPAW electronic-structure code [46][47][48] are described in Secs. II and III.…”