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Measurements of Nonequilibrium Interatomic Forces in Photoexcited Bismuth

Materials Science 2021-05-26 v1

Abstract

We determine experimentally the excited-state interatomic forces in photoexcited bismuth. The forces are obtained by a constrained least-squares fit of the excited-state dispersion obtained by femtosecond time-resolved x-ray diffuse scattering to a fifteen-nearest neighbor Born-von Karman model. We find that the observed softening of the zone-center A1gA_{1g} optical mode and transverse acoustic modes with photoexcitation are primarily due to a weakening of three nearest neighbor forces along the bonding direction. This provides a more complete picture of what drives the partial reversal of the Peierls distortion previously observed in photoexcited bismuth.

Keywords

Cite

@article{arxiv.1908.07161,
  title  = {Measurements of Nonequilibrium Interatomic Forces in Photoexcited Bismuth},
  author = {Samuel W. Teitelbaum and Thomas C. Henighan and Hanzhe Liu and Mason P. Jiang and Diling Zhu and Matthieu Chollet and Takahiro Sato and Éamonn D. Murray and Stephen Fahy and Shane O'Mahony and Trevor P. Bailey and Ctirad Uher and Mariano Trigo and David A. Reis},
  journal= {arXiv preprint arXiv:1908.07161},
  year   = {2021}
}

Comments

6 pages, 3 figures, plus 3 pages, 3 figures of supplemental information