Show simple item record
dc.description.sponsorshipGefördert durch den Publikationsfonds der Universität Kassel
dc.rightsUrheberrechtlich geschützt
dc.subjectComputational physicseng
dc.subjectMaterials scienceeng
dc.subjectSemiconductor physicseng
dc.titleSqueezed thermal phonons precurse nonthermal melting of silicon as a function of fluenceeng
dcterms.abstractA 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.eng
dcterms.accessRightsopen access
dcterms.bibliographicCitationIn: Physical review. X, Expanding access. College Park, Md. : APS, Vol. 3 (2013), 1, 011005, 1-8
dcterms.creatorZijlstra, Eeuwe S.
dcterms.creatorKalitsov, Alan
dcterms.creatorZier, Tobias
dcterms.creatorGarcia, Martin E.

Files in this item


This item appears in the following Collection(s)

Show simple item record