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Bibliographic Details
Main Authors: Zier, Tobias, Zijlstra, Eeuwe S., Garcia, Martin E., Strubbe, David A.
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2306.08159
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author Zier, Tobias
Zijlstra, Eeuwe S.
Garcia, Martin E.
Strubbe, David A.
author_facet Zier, Tobias
Zijlstra, Eeuwe S.
Garcia, Martin E.
Strubbe, David A.
contents An intense femtosecond-laser excitation of a solid induces highly nonthermal conditions. In materials like silicon, laser-induced bond-softening leads to a highly incoherent ionic motion and eventually nonthermal melting. But is this outcome an inevitable consequence, or can it be controlled? Here, we performed ab initio molecular dynamics simulations of crystalline silicon after timed multiple femtosecond-laser pulse excitations with fluence above the nonthermal melting threshold. Our results demonstrate an excitation mechanism that pauses nonthermal melting and creates a metastable state instead, with an electronic structure similar to the ground state. This mechanism can be generalized to other materials, potentially enabling structural and/or electronic transitions to metastable phases in the high-excitation regime. In addition, our approach could be used to switch off nonthermal contributions in experiments, allowing reliable electron-phonon coupling constants to be obtained more easily.
format Preprint
id arxiv_https___arxiv_org_abs_2306_08159
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Pausing ultrafast melting by timed multiple femtosecond-laser pulses
Zier, Tobias
Zijlstra, Eeuwe S.
Garcia, Martin E.
Strubbe, David A.
Materials Science
An intense femtosecond-laser excitation of a solid induces highly nonthermal conditions. In materials like silicon, laser-induced bond-softening leads to a highly incoherent ionic motion and eventually nonthermal melting. But is this outcome an inevitable consequence, or can it be controlled? Here, we performed ab initio molecular dynamics simulations of crystalline silicon after timed multiple femtosecond-laser pulse excitations with fluence above the nonthermal melting threshold. Our results demonstrate an excitation mechanism that pauses nonthermal melting and creates a metastable state instead, with an electronic structure similar to the ground state. This mechanism can be generalized to other materials, potentially enabling structural and/or electronic transitions to metastable phases in the high-excitation regime. In addition, our approach could be used to switch off nonthermal contributions in experiments, allowing reliable electron-phonon coupling constants to be obtained more easily.
title Pausing ultrafast melting by timed multiple femtosecond-laser pulses
topic Materials Science
url https://arxiv.org/abs/2306.08159