SurfaceScience21 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 70: Poster Session V: Poster to Mini-Symposium: Frontiers of electronic-structure theory II

O 70.6: Poster

Mittwoch, 3. März 2021, 10:30–12:30, P

Excited Electron Enhanced Defect Diffusion in MgO under Ultrafast Laser Irradiation — •Yifan Yao and Andre Schleife — University of Illinois, Urbana-Champaign

Electronic excitation of defect states has been predicted to enhance ion diffusion via manipulating the explicit electron distribution. Due to the induced non-linear excitation, the ultrafast laser can offer a novel opportunity to control the electron dynamics in materials. Hence, a detailed understanding of laser-materials interaction is vital for manufacturing with nanoscale precision but still remains unclear, due to its non-linear and non-equilibrium character. Here, we use oxygen vacancy migration in MgO as an example to study the ion diffusion in laser-irradiated materials. We apply real-time TDDFT, which can accurately describe such nonlinear effects, to calculate the time-evolution of the occupation number under different laser frequencies and intensities. Comparison to the distribution of hot electrons following proton irradiation can provide insights into how diffusion enhancement can be achieved by the transient localized electron dynamics and how it depends on specific laser parameters.

We acknowledge ONR N00014-18-1-2605 for financial support.