Publication
Title
Accurate description of the van der Waals interaction of an electron-positron pair with the surface of a topological insulator
Author
Abstract
Positrons can be trapped in localized states at the surface of a material, and thus quite selectively interact with core or valence surface electrons. Hence, advanced surface positron spectroscopy techniques can present the ideal tools to study a topological insulator, where surface states play a fundamental role. We analyze the problem of a positron at a TI surface, assuming that it is a weakly physisorbed positronium (Ps) atom. To determine if the surface of interest in a material can sustain such a physisorption, an accurate description of the underlying van der Waals (vdW) interaction is essential. We have developed a first-principles parameterfree method, based on the density functional theory, to extract key parameters determining the vdW interaction potential between a Ps atom and the surface of a given material. The method has been successfully applied to quartz and preliminary results on Bi2Te2Se indicate the existence of a positron surface state. We discuss the robustness of our predictions versus the most relevant approximations involved in our approach.
Language
English
Source (journal)
Journal of physics : conference series. - Bristol
Publication
Bristol : 2014
ISSN
1742-6588 [print]
1742-6596 [online]
Volume/pages
505(2014), 4 p.
Article Reference
012002
ISI
000338216500002
Medium
E-only publicatie
Full text (Publishers DOI)
Full text (publishers version - intranet only)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 19.08.2014
Last edited 30.04.2017
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