Simulations of laser-induced dynamics in free-standing thin silicon films

Zier, Tobias; Zijlstra, Eeuwe S.; Krylow, Sergej; Garcia, Martín E.

doi:10.1007/s00339-017-1230-9

Cited by 8 publications

(3 citation statements)

References 46 publications

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“…Silicon is a widely studied material in the context of strongly driven phase transitions, both experimentally [1][2][3][4][5][6] and theoretically [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], where it is found to melt on a subpicosecond timescale at high excitations. Most theoretical studies of nonthermal melting in silicon have employed ab initio simulation methods.…”

Section: Introductionmentioning

confidence: 99%

Simulating electronically driven structural changes in silicon with two-temperature molecular dynamics

Darkins

Murphy

et al. 2018

Phys. Rev. B

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Radiation can drive the electrons in a material out of thermal equilibrium with the nuclei, producing hot, transient electronic states that modify the interatomic potential energy surface. We present a rigorous formulation of two-temperature molecular dynamics that can accommodate these electronic effects in the form of electronic-temperature-dependent force fields. Such a force field is presented for silicon, which has been constructed to reproduce the ab initio-derived thermodynamics of the diamond phase for electronic temperatures up to 2.5 eV, as well as the structural dynamics observed experimentally under nonequilibrium conditions in the femtosecond regime. This includes nonthermal melting on a subpicosecond timescale to a liquidlike state for electronic temperatures above ∼1 eV. The methods presented in this paper lay a rigorous foundation for the large-scale atomistic modeling of electronically driven structural dynamics with potential applications spanning the entire domain of radiation damage.

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Section: Introductionmentioning

confidence: 99%

Simulating electronically driven structural changes in silicon with two-temperature molecular dynamics

Darkins

Murphy

et al. 2018

Phys. Rev. B

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“…We perform ab-initio simulation of laser-excited solids by using the T e -dependent DFT code CHIVES [14][15][16][17][18], which was developed in our group. We implemented the local density approximation (LDA) in CHIVES.…”

Section: Ab-initio Code Chivesmentioning

confidence: 99%

“…The diagonalization is efficiently performed using optimized linear algebra package (LAPACK) subroutines. The Pulay-Kerker mixer is applied in the self-consistent cycle for solving the Kohn-Sham equations, which allows also the treatment of surfaces [16]. Furthermore, the self-consistent cycle is efficiently initialized by using a charge density extrapolation from previous time steps.…”

Section: Ab-initio Code Chivesmentioning

confidence: 99%

Universal behavior of the band gap as a function of the atomic mean-square displacement in laser-excited silicon

Bauerhenne

Garcia

2020

Advanced Optical Technologies

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AbstractWe performed systematic ab-initio molecular dynamics (MD) simulations of fs-laser-excited silicon (Si) using the Te-dependent density functional theory (DFT). We considered the case in which the potential energy surface (PES) is strongly modified by the laser excitation, so that nonthermal melting occurs. We analyzed the correlation between the time dependence of electronic properties like the band gap and the laser-induced atomic motion. Surprisingly, we found that the indirect electronic band gap decreases as a universal function of the atomic mean-square displacement (MSD) almost independently of the electronic temperature (laser fluence) and that the dependence is linear for a wide range of MSDs. We also found that a universal dependence is also present when analyzing the band gap as a function of the relative Bragg peak intensities, which can be directly measured in experiments.

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Ab-initio Description of a Fs-laser Excitation

Bauerhenne

2021

Materials Interaction With Femtosecond Lasers

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Simulations of laser-induced dynamics in free-standing thin silicon films

Cited by 8 publications

References 46 publications

Simulating electronically driven structural changes in silicon with two-temperature molecular dynamics

Simulating electronically driven structural changes in silicon with two-temperature molecular dynamics

Universal behavior of the band gap as a function of the atomic mean-square displacement in laser-excited silicon

Ab-initio Description of a Fs-laser Excitation

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