Measurements of Nonequilibrium Interatomic Forces in Photoexcited Bismuth

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 $A_{1g}$ 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.

arXiv comment6 pages, 3 figures, plus 3 pages, 3 figures of supplemental information

References in corpus (9)

• An optically stimulated superconducting-like phase in K3C60 far above equilibrium Tc
• Nonlinear phononics: A new ultrafast route to lattice control
• Light-Induced Charge Density Wave in LaTe${}_3$
• Beyond the molecular movie: dynamics of bands and bonds during a photo-induced phase transition
• Real-time observation of a coherent lattice transformation into a high-symmetry phase
• Phonon Spectroscopy with Sub-meV Resolution by Femtosecond X-ray Diffuse Scattering
• Direct Measurement of Anharmonic Decay Channels of a Coherent Phonon
• Charge density wave melting in one-dimensional wires with femtosecond sub-gap excitation
• How to distinguish squeezed and coherent phonons in femtosecond x-ray diffuse scattering

Cited by in corpus (4)

• Direct view of phonon dynamics in atomically thin MoS${}_2$
• Ultrafast Suppression of the Ferroelectric Instability in KTaO${}_3$
• Ultrafast Electron Diffraction: Visualizing Dynamic States of Matter
• A modular table-top setup for ultrafast X-ray diffraction