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Unified ab initio description of the ultrafast reversible and irreversible laser-induced structural changes occurring in antimony: from coherent phonons up to nonthermal melting

锑中发生的超快可逆和不可逆激光诱导结构变化的统一从头描述：从相干声子到非热熔化

基本信息

批准号：
262778930
负责人：
Professor Dr. Martin Ezequiel Garcia
金额：
--
依托单位：
Theoretische Physik II: Festkörper und Ultrakurzzeitphysik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/262778930?language=en
关键词：
Unified ab initio description ultrafast

项目摘要

Femtosecond-laser pulses are known to create extreme nonequilibrium conditions in solids: Whereas the electrons are heated to several 10000 K, the ions remain close to room temperature. In this proposal we plan to perform, for the first time, a detailed study of the atomic pathways triggered by the changes in the bonding properties of solid antimony due to the laser excitation of hot electrons over a broad range of laser fluences up to the (nonthermal) melting threshold. Antimony is a particularly interesting material, since it is expected to exhibit all so far known laser-induced ultrafast structural phenomena, namely, coherent phonons, thermal phonon squeezing, solid-solid phase transitions, and nonthermal melting. In order to resolve the microscopic pathways followed by the atoms we intend to employ a molecular dynamics code based on Mermin's electronic-temperature-dependent density functional theory that has been recently written in our group. This so-called Code for Highly-excited Valence Electron Systems (CHIVES) uses local basis sets and order(N) methods for the construction of the Hamiltonian and overlap matrices and has been shown to be about two hundred times faster than state-of-the-art plane-wave codes. At present we can perform simulations of supercells with up to 1200 atoms. Ultrafast structural phenomena can be experimentally detected by all-optical pump-probe measurements of the reflectivity and more recently also directly using time-resolved electron- or x-ray-diffraction. Our analysis will yield time-dependent structure factors, which will, among other applications, be important for the interpretation of experiments planned at new x-ray free-electron-laser facilities, such as, FLASH in Hamburg and LCLS in Stanford.

众所周知，飞秒激光脉冲会在固体中产生极端的非平衡状态：当电子被加热到10000 K时，离子仍然接近室温。在本提案中，我们计划首次对固体锑的键合特性变化所引发的原子路径进行详细研究，这是由于激光激发热电子在广泛的激光影响范围内达到（非热）熔化阈值。锑是一种特别有趣的材料，因为它有望表现出迄今为止已知的所有激光诱导的超快结构现象，即相干声子、热声子压缩、固-固相变和非热熔化。为了解决原子所遵循的微观路径，我们打算采用基于Mermin的电子温度依赖密度泛函理论的分子动力学代码，该理论最近在我们小组中编写。这种所谓的高激发价电子系统代码（CHIVES）使用局部基集和阶(N)方法来构造哈密顿矩阵和重叠矩阵，并且已被证明比最先进的平面波代码快大约200倍。目前，我们可以模拟多达1200个原子的超级电池。超快结构现象可以通过反射率的全光泵浦探针测量来实验检测，最近也直接使用时间分辨电子或x射线衍射来检测。我们的分析将产生与时间相关的结构因子，这对于解释计划在新的x射线自由电子激光设施（如汉堡的FLASH和斯坦福的LCLS）进行的实验非常重要。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Quasimomentum-Space Image for Ultrafast Melting of Silicon.

硅超快熔化的拟动量空间图像

DOI：
10.1103/physrevlett.116.153901
发表时间：
2016
期刊：
Physical review letters
影响因子：
8.6
作者：
T. Zier;E. S. Zijlstra;M. E. Garcia
通讯作者：
M. E. Garcia

Ab initio molecular dynamics simulations of femtosecond-laser-induced anti-Peierls transition in antimony

飞秒激光诱导反 Peierls 转变为锑的从头算分子动力学模拟

DOI：
10.1117/12.2214668
发表时间：
2016
期刊：
影响因子：
0
作者：
E. S. Zijlstra;T. Zier;B. Bauerhenne;S. Krylow;M. E. Garcia
通讯作者：
M. E. Garcia

Coherent and incoherent structural dynamics in laser-excited antimony

激光激发锑的相干和非相干结构动力学

DOI：
10.1103/physrevb.95.054302
发表时间：
2017
期刊：
Physical Review B
影响因子：
3.7
作者：
L. Waldecker;Th. Vasileiadis;R. Bertoni;R. Ernstorfer;T. Zier;F. H. Valencia;M. E. Garcia;E. S. Zijlstra
通讯作者：
E. S. Zijlstra

Molecular dynamics simulations of a femtosecond-laser-induced solid-to-solid transition in antimony