Ultrafast electron diffuse scattering as a tool for studying phonon transport: Phonon hydrodynamics and second sound oscillations.
| Autor: | Kremeyer L; Department of Physics, Center for the Physics of Materials, McGill University, Montreal, Quebec H3A 2T8, Canada., Britt TL; Department of Physics, Center for the Physics of Materials, McGill University, Montreal, Quebec H3A 2T8, Canada., Siwick BJ, Huberman SC; Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada. |
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| Jazyk: | angličtina |
| Zdroj: | Structural dynamics (Melville, N.Y.) [Struct Dyn] 2024 Mar 12; Vol. 11 (2), pp. 024101. Date of Electronic Publication: 2024 Mar 12 (Print Publication: 2024). |
| DOI: | 10.1063/4.0000224 |
| Abstrakt: | Hydrodynamic phonon transport phenomena, like second sound, have been observed in liquid helium more than 50 years ago. More recently second sound has been observed in graphite at over 200 K using transient thermal grating (TG) techniques. In this work, we explore signatures of phonon hydrodynamic transport and second sound oscillations in ultrafast electron diffuse scattering patterns, which can provide time, momentum, and branch resolved information on the state-of-excitation of the phonon system beyond that available through TG experiments. We use the density functional theory and solve the Boltzmann transport equation to determine time-resolved non-equilibrium phonon populations and model phonon transport in graphite. This model also provides the information necessary to calculate the time evolution of one-phonon structure factors and diffuse scattering patterns during thermal transport covering ballistic, diffusive, and hydrodynamic regimes where the effect of a second sound oscillation on the phonon distribution is observed. Direct measurements of how the phonon distribution varies in time and space in various thermal transport regimes should yield new insights into the fundamental physics of the underlying processes. Competing Interests: The authors have no conflicts to disclose. (© 2024 Author(s).) |
| Databáze: | MEDLINE |
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