Publication
Title
Application of the weighted-density approximation to the accurate description of electron-positron correlation effects in materials
Author
Abstract
We discuss positron-annihilation lifetimes for a set of illustrative bulk materials within the framework of the weighted-density approximation (WDA). The WDA can correctly describe electron-positron correlations in strongly inhomogeneous systems, such as surfaces, where the applicability of (semi-) local approximations is limited. We analyze the WDA in detail and show that the electrons which cannot screen external charges efficiently, such as the core electrons, cannot be treated accurately via the pair correlation of the homogeneous electron gas. We discuss how this problem can be addressed by reducing the screening in the homogeneous electron gas by adding terms depending on the gradient of the electron density. Further improvements are obtained when core electrons are treated within the LDA and the valence electron using the WDA. Finally, we discuss a semiempirical WDA-based approach in which a sum rule is imposed to reproduce the experimental lifetimes.
Language
English
Source (journal)
Physical review B / American Physical Society. - New York, N.Y, 2016, currens
Publication
New York, N.Y : American Physical Society , 2017
ISSN
2469-9969 [online]
2469-9950 [print]
DOI
10.1103/PHYSREVB.96.085135
Volume/pages
96 :8 (2017) , 13 p.
Article Reference
085135
ISI
000408342600003
Medium
E-only publicatie
Full text (Publisher's DOI)
Full text (open access)
UAntwerpen
Faculty/Department
Research group
Project info
First-principles positron spectroscopy of topological insulators.
CalcUA as central calculation facility: supporting core facilities.
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identifier
Creation 03.10.2017
Last edited 22.01.2024
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