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Toward precise simulations of the coupled ultrafast dynamics of electrons and atomic vibrations in materials

Tong, Xiao and Bernardi, Marco (2020) Toward precise simulations of the coupled ultrafast dynamics of electrons and atomic vibrations in materials. . (Unpublished) https://resolver.caltech.edu/CaltechAUTHORS:20201005-102911333

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Abstract

Ultrafast spectroscopies can access the dynamics of electrons and nuclei at short timescales, shedding light on nonequilibrium phenomena in materials. However, development of accurate calculations to interpret these experiments has lagged behind as widely adopted simulation schemes are limited to sub-picosecond timescales or employ simplified interactions lacking quantitative accuracy. Here we show a precise approach to obtain the time-dependent populations of nonequilibrium electrons and atomic vibrations (phonons) up to tens of picoseconds, with a femtosecond time resolution. Combining first-principles electron-phonon and phonon-phonon interactions with a parallel numerical scheme to time-step the coupled electron and phonon Boltzmann equations, our method provides unprecedented microscopic insight into scattering mechanisms in excited materials. Focusing on graphene as a case study, we demonstrate calculations of ultrafast electron and phonon dynamics, transient optical absorption, structural snapshots and diffuse X-ray scattering. Our first-principles approach paves the way for quantitative atomistic simulations of ultrafast dynamics in materials.


Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription
http://arxiv.org/abs/2009.07958arXivDiscussion Paper
ORCID:
AuthorORCID
Bernardi, Marco0000-0001-7289-9666
Additional Information:The authors thank Jin-Jian Zhou for fruitful discussions. X.T. thanks the Resnick Sustainability Institute at the California Institute of Technology for fellowship support. This work was partially supported by the National Science Foundation under Grant No. DMR-1750613, which provided for theory development, and by the Department of Energy under Grant No. DE-SC0019166, which provided for numerical calculations and code development. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Author Contributions: M.B. conceived the research. X.T. developed the computational codes and carried out the calculations. All authors analyzed the results and wrote the manuscript. The authors declare no competing financial interests. Data Availability: The datasets generated and/or analyzed in the current study are available from the corresponding author upon reasonable request.
Group:Resnick Sustainability Institute
Funders:
Funding AgencyGrant Number
Resnick Sustainability InstituteUNSPECIFIED
NSFDMR-1750613
Department of Energy (DOE)DE-SC0019166
Department of Energy (DOE)DE-AC02-05CH11231
Record Number:CaltechAUTHORS:20201005-102911333
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20201005-102911333
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:105784
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:05 Oct 2020 17:50
Last Modified:05 Oct 2020 17:50

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