Aufsatz
Artikel (Publikationen im Open Access gefördert durch die UB)
Squeezed thermal phonons precurse nonthermal melting of silicon as a function of fluence
Abstract
A femtosecond-laser pulse can induce ultrafast nonthermal melting of various materials along pathways
that are inaccessible under thermodynamic conditions, but it is not known whether there is any structural
modification at fluences just below the melting threshold. Here, we show for silicon that in this regime the
room-temperature phonons become thermally squeezed, which is a process that has not been reported
before in this material. We find that the origin of this effect is the sudden femtosecond-laser-induced
softening of interatomic bonds, which can also be described in terms of a modification of the potential
energy surface. We further find in ab initio molecular-dynamics simulations on laser-excited potential
energy surfaces that the atoms move in the same directions during the first stages of nonthermal melting
and thermal phonon squeezing. Our results demonstrate how femtosecond-laser-induced coherent
fluctuations precurse complete atomic disordering as a function of fluence. The common underlying
bond-softening mechanism indicates that this relation between thermal squeezing and nonthermal melting
is not material specific.
that are inaccessible under thermodynamic conditions, but it is not known whether there is any structural
modification at fluences just below the melting threshold. Here, we show for silicon that in this regime the
room-temperature phonons become thermally squeezed, which is a process that has not been reported
before in this material. We find that the origin of this effect is the sudden femtosecond-laser-induced
softening of interatomic bonds, which can also be described in terms of a modification of the potential
energy surface. We further find in ab initio molecular-dynamics simulations on laser-excited potential
energy surfaces that the atoms move in the same directions during the first stages of nonthermal melting
and thermal phonon squeezing. Our results demonstrate how femtosecond-laser-induced coherent
fluctuations precurse complete atomic disordering as a function of fluence. The common underlying
bond-softening mechanism indicates that this relation between thermal squeezing and nonthermal melting
is not material specific.
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Citation
@article{urn:nbn:de:hebis:34-2013093044056,
author={Zijlstra, Eeuwe S. and Kalitsov, Alan and Zier, Tobias and Garcia, Martin E.},
title={Squeezed thermal phonons precurse nonthermal melting of silicon as a function of fluence},
year={2013}
}
0500 Oax 0501 Text $btxt$2rdacontent 0502 Computermedien $bc$2rdacarrier 1100 2013$n2013 1500 1/ 2050 ##0##urn:nbn:de:hebis:34-2013093044056 3000 Zijlstra, Eeuwe S. 3010 Kalitsov, Alan 3010 Zier, Tobias 3010 Garcia, Martin E. 4000 Squeezed thermal phonons precurse nonthermal melting of silicon as a function of fluence / Zijlstra, Eeuwe S. 4030 4060 Online-Ressource 4085 ##0##=u http://nbn-resolving.de/urn:nbn:de:hebis:34-2013093044056=x R 4204 \$dAufsatz 4170 7136 ##0##urn:nbn:de:hebis:34-2013093044056
<resource xsi:schemaLocation="http://datacite.org/schema/kernel-2.2 http://schema.datacite.org/meta/kernel-2.2/metadata.xsd"> 2013-09-30T09:53:21Z 2013-09-30T09:53:21Z 2013 urn:nbn:de:hebis:34-2013093044056 http://hdl.handle.net/123456789/2013093044056 Gefördert durch den Publikationsfonds der Universität Kassel Urheberrechtlich geschützt https://rightsstatements.org/page/InC/1.0/ Computational physics Materials science Semiconductor physics 530 Squeezed thermal phonons precurse nonthermal melting of silicon as a function of fluence Aufsatz A femtosecond-laser pulse can induce ultrafast nonthermal melting of various materials along pathways that are inaccessible under thermodynamic conditions, but it is not known whether there is any structural modification at fluences just below the melting threshold. Here, we show for silicon that in this regime the room-temperature phonons become thermally squeezed, which is a process that has not been reported before in this material. We find that the origin of this effect is the sudden femtosecond-laser-induced softening of interatomic bonds, which can also be described in terms of a modification of the potential energy surface. We further find in ab initio molecular-dynamics simulations on laser-excited potential energy surfaces that the atoms move in the same directions during the first stages of nonthermal melting and thermal phonon squeezing. Our results demonstrate how femtosecond-laser-induced coherent fluctuations precurse complete atomic disordering as a function of fluence. The common underlying bond-softening mechanism indicates that this relation between thermal squeezing and nonthermal melting is not material specific. open access In: Physical review. X, Expanding access. College Park, Md. : APS, Vol. 3 (2013), 1, 011005, 1-8 Zijlstra, Eeuwe S. Kalitsov, Alan Zier, Tobias Garcia, Martin E. doi:10.1103/PhysRevX.3.011005 </resource>
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