Einheitliche ab-initio Beschreibung ultraschneller reversibler und irreversibler laser-induzierter Strukturänderungen, die in Antimon auftreten: von kohärenten Phononen bis zum nichtthermischen Schmelzen
Zusammenfassung der Projektergebnisse
During this project we have studied ultrafast nonequilibrium structural changes in Silicon and Antimony. We have shown that the transient nonequilibrium state generated in Silicon and Antimony by ultrashort intense laser pulses makes ultrafast structural transitions possible, which in thermodynamical equilibrium would become inaccessible. We were able to identify signatures of nonthermal melting which makes it qualitatively different from the well-studied thermal melting. For example, we have demonstrated that the appearance of lattice instabilities and of extreme anisotropic energy-exchange processes is typical for nonthermal phase transitions. Moreover, we performed first principles atomistic simulations on Sb and compared the laser induced ultrafast ionic dynamics with experiments. Our simulations yielded very good agreement with experimentally measured Bragg-peak time evolutions. We succeeded, in collaboration with our experimental partners, in determining the role of coherent and incoherent electron-phonon coupling on the ultrashort dynamics of Sb. Our works served as a basis for further investigations and were published in internationally well-respected journals.
Projektbezogene Publikationen (Auswahl)
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Melting of Al induced by laser excitation of 2p holes, Mater. Res. Lett. 3, 149-155 (2015)
Y. Rosandi, F. Cheenicode Kabeer, Y. Cherednikov, E. S. Zijlstra, M. E. Garcia, N. A. Inogamov, and H. M. Urbassek
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Signatures of nonthermal melting, Structural Dynamics 2 , 054101 (2015)
T. Zier , E. S. Zijlstra, A. Kalitsov, I. Theodonis and M. E. Garcia
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Ab initio molecular dynamics simulations of femtosecond-laser-induced anti-Peierls transition in antimony, Proc. SPIE 9735, 97350K (2016)
E. S. Zijlstra, T. Zier, B. Bauerhenne, S. Krylow, M. E. Garcia
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Quasimomentum-Space Image for Ultrafast Melting of Silicon, Phys. Rev. Lett. 116, 153901 (2016)
T. Zier, E. S. Zijlstra, M. E. Garcia
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Coherent and Incoherent Structual Dynamics in Laser- Excited Antimony, Phys. Rev. B 95, 054302 (2017)
L. Waldecker, Th. Vasileiadis, R. Bertoni, R. Ernstorfer, T. Zier, F. H. Valencia, M. E. Garcia and E. S. Zijlstra
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Modelling ultrafast laser ablation , J. Phys. D: Appl. Phys. 50, 193001 (2017)
B. Rethfeld, Dmitriy S. Ivanov, M. E. Garcia, and S. I. Anisimov
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Molecular dynamics simulations of a femtosecond-laser-induced solid-to-solid transition in antimony, Appl. Phys. A 123, 608 (2017)
B. Bauerhenne, E. S. Zijlstra, M. E. Garcia
