Regensburg 2019 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 65: Poster Wednesday: Surface Structure, Epitaxy and Growth

O 65.16: Poster

Mittwoch, 3. April 2019, 17:45–20:00, Poster B1

Thermal motion slows down the In/Si(111)(8x2)-(4x1) phase transition — •Marvin Krenz, Uwe Gerstmann, and Wolf Gero Schmidt — Lehrstuhl für Theoretische Materialphysik, Universität Paderborn, 33095 Paderborn

The optically induced In/Si(111)(8x2)-(4x1) insulator-metal transition serves as a prototypical model for the interplay of electronic and structural degrees of freedom during photoreactions [1,2]. Interestingly, at 20 K, the photo-induced (8x2)-(4x1)phase transition occurs extremely fast, in the quantum limit, and requires only a few hundred femtoseconds [1]. Here we present ab initio molecular dynamics calculations on excited-state potential energy surfaces based on constrained DFT. The calculations that account for temperature effects at 100 K indicate that thermal motion has a small effect on the transition time with a tendency to a slightly slow down the transition.

[1] T Frigge et al., Nature 544, 207 (2017). [2] CW Nicholson et al., Science 362, 821 (2018).