2001/08/24 by Silvia Picozzi, S. Picozzi, Ryoji Asahi +5 · 1 citation
Engineering · Physics and Astronomy · #Quantum and electron transport phenomena #Radiation Effects in Electronics #Semiconductor Quantum Structures and Devices #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.65.113206
11 pages, 4 figures, Submitted to Phys. Rev. B
arxiv created 2001/08/24 · openalex publication_date 2002/02/28 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Results are presented of a fully ab initio calculation of impact ionization rates in GaAs within the density functional theory framework, using a screened-exchange formalism and the highly precise all-electron full-potential linearized augmented plane wave method. The calculated impact ionization rates show a marked orientation dependence in k space, indicating the strong restrictions imposed by the conservation of energy and momentum. This anisotropy diminishes as the impacting electron energy increases. A Keldysh type fit performed on the energy-dependent rate shows a rather soft edge and a threshold energy greater than the direct band gap. The consistency with available Monte Carlo and empirical pseudopotential calculations shows the reliability of our approach and paves the way to ab initio calculations of pair production rates in new and more complex materials.