Light-induced atomic motion in ionic crystals
Abstract
Atomic motion in solids is conventionally driven by elastic collisions between ionizing particles and atoms, which transfer momentum and induce lattice displacements. In this work, we demonstrate a different mechanism for atomic displacement based on optical excitation of scintillating ionic crystals. Ionic crystals are unique systems because of the closed-shell electronic configuration of their constituent ions. In these materials, excitation above the band gap generates a hole that strongly distorts the lattice, resulting in the formation of a self-trapped hole (STH). The STH is Coulomb-attracted to the electron, thereby forming a self-trapped exciton (STE). Here, we demonstrate that in BaF2 - one of the fastest scintillators - the STE structure promotes the formation of long-lived electron and hole traps that persist in the lattice at room temperature. Such trapped electron-hole pairs occupy vacancy-interstitial fluorine pair positions, and can be created indiscernibly using optical or ionizing radiation excitation, as long as the STH is formed. Further, we demonstrate that it is possible to control the defect evolution with light. Selective optical stimulation of the trapped electrons or holes enables the regeneration of the STE at later times. This light-controlled defect engineering allows us to increase the yield of the STE signal appearing as optically stimulated luminescence (OSL) and to image the spatial distribution of the initial energy deposition, holding strong potential for ionizing-radiation detection. These findings provide a common framework underlying scintillation and OSL in ionic crystals of the fluorite structure, allowing for optical manipulation of atomic vacancies-interstitial pairs in similar systems.
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BibTeX
@misc{warming2026lightinduced,
title = {{Light-induced atomic motion in ionic crystals}},
author = {Jacob C. Warming and Simon P. S. Jessen and Emma A. Husted and Jan Thøgersen and Stefan Gundacker and Brian Julsgaard and Peter Balling and Rosana M. Turtos},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.28143},
eprint = {2608.28143},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.28143},
}
RIS
TY - UNPB
TI - Light-induced atomic motion in ionic crystals
AU - Jacob C. Warming
AU - Simon P. S. Jessen
AU - Emma A. Husted
AU - Jan Thøgersen
AU - Stefan Gundacker
AU - Brian Julsgaard
AU - Peter Balling
AU - Rosana M. Turtos
PY - 2026
DA - 2026/08/28
PB - arXiv
DO - 10.48550/arxiv.2608.28143
UR - https://arxiv.org/abs/2608.28143
AB - Atomic motion in solids is conventionally driven by elastic collisions between ionizing particles and atoms, which transfer momentum and induce lattice displacements. In this work, we demonstrate a different mechanism for atomic displacement based on optical excitation of scintillating ionic crystals. Ionic crystals are unique systems because of the closed-shell electronic configuration of their constituent ions. In these materials, excitation above the band gap generates a hole that strongly distorts the lattice, resulting in the formation of a self-trapped hole (STH). The STH is Coulomb-attracted to the electron, thereby forming a self-trapped exciton (STE). Here, we demonstrate that in BaF2 - one of the fastest scintillators - the STE structure promotes the formation of long-lived electron and hole traps that persist in the lattice at room temperature. Such trapped electron-hole pairs occupy vacancy-interstitial fluorine pair positions, and can be created indiscernibly using optical or ionizing radiation excitation, as long as the STH is formed. Further, we demonstrate that it is possible to control the defect evolution with light. Selective optical stimulation of the trapped electrons or holes enables the regeneration of the STE at later times. This light-controlled defect engineering allows us to increase the yield of the STE signal appearing as optically stimulated luminescence (OSL) and to image the spatial distribution of the initial energy deposition, holding strong potential for ionizing-radiation detection. These findings provide a common framework underlying scintillation and OSL in ionic crystals of the fluorite structure, allowing for optical manipulation of atomic vacancies-interstitial pairs in similar systems.
ER -