@article{23a7e13f58434a3eb83990c19869f47a,
title = "Measurements of nonequilibrium interatomic forces using time-domain x-ray scattering",
abstract = "We demonstrate an experimental approach to determining the excited-state interatomic forces using femtosecond x-ray pulses from an x-ray free-electron laser. We determine experimentally the excited-state interatomic forces that connect photoexcited carriers to the nonequilibrium lattice dynamics in the prototypical Peierls-distorted material, bismuth. The forces are obtained by a constrained least-squares fit of a pairwise interatomic force model to the excited-state phonon dispersion relation as measured by the time- and momentum-resolved x-ray diffuse scattering. We find that photoexcited carriers weaken predominantly the nearest-neighbor forces, which drives the measured softening of the transverse acoustic modes throughout the Brillouin zone as well as the zone-center A1g optical mode. This demonstrates a bond-selective approach to measuring electron-phonon coupling relevant to a broad range of photoinduced phase transitions and transient light-driven states in quantum materials.",
author = "Teitelbaum, {Samuel W.} and Henighan, {Thomas C.} and Hanzhe Liu and Jiang, {Mason P.} and Diling Zhu and Matthieu Chollet and Takahiro Sato and Murray, {{\'E}amonn D.} and Stephen Fahy and Shane O'Mahony and Bailey, {Trevor P.} and Ctirad Uher and Mariano Trigo and Reis, {David A.}",
note = "Funding Information: The authors thank Roberto Merlin for insightful discussions on the manuscript. This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, through the Division of Materials Sciences and Engineering under Contract No. DE-AC02-76SF00515. C.U. and T.P.B. acknowledge support from the U.S. Department of Energy, Office of Basic Energy Sciences, under Award No. DE-SC-0008574. Work at the Tyndall National Institute was supported by Science Foundation Ireland Award No. 12/IA/1601 and Irish Research Council Award No. GOIPG/2015/2784. Measurements were carried out at the Linac Coherent Light Source, a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences. Preliminary measurements were performed at the Stanford Synchrotron Radiation Lightsource (Beamline 7-2), SLAC National Accelerator Laboratory. Publisher Copyright: {\textcopyright} 2021 American Physical Society.",
year = "2021",
month = may,
day = "18",
doi = "10.1103/PhysRevB.103.L180101",
language = "English (US)",
volume = "103",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "18",
}