Interplay of thermal and non-thermal effects in x-ray-induced ultrafast melting

• DOI: 10.48550/arxiv.2308.14560
• Publication Date: 2023-01-01
• Authors: Ichiro Inoue; В. І. Ткаченко; Yuya Kubota; F. Dorchies; Toru Hara; H. Hoeppner; Yuichi Inubushi; Konrad Jerzy Kapcia; Hae Ja Lee; Vladimir Lipp; Paloma Martinez; Eiji Nishibori; Taito Osaka; S. Toleikis; Jumpei Yamada; Makina Yabashi; Beata Ziaja; Philip Heimann
• Keywords: Thermal equilibrium

X-ray laser-induced structural changes in silicon undergoing femtosecond melting have been investigated by using an x-ray pump-x-ray probe technique. The experimental results for different initial sample temperatures reveal that the onset time and speed of atomic disordering are independent temperature, suggesting equilibrium motion state does not play a pivotal role x-ray-induced ultrafast melting. By comparing observed time-dependence dedicated theoretical simulations, we interpret energy transfer from excited electrons to ions via electron-ion coupling (thermal effect) as well strong modification interatomic potential due electron excitations (non-thermal trigger disordering. Our finding interplay thermal non-thermal effects demonstrates accurate modeling intense interactions with matter is essential ensure correct interpretation experiments laser pulses.