In the hydrodynamic regime, phonons drift with a nonzero collective velocity under a temperature gradient, reminiscent of viscous gas and fluid flow. The study of hydrodynamic phonon transport has spanned over half a century but has been mostly limited to cryogenic temperatures (<20 K). Recently, we predict based on first principles calculations that hydrodynamic phonon transport can occur in suspended graphene at significantly higher temperatures and wider temperature ranges compared to bulk materials. Furthermore, we identified graphite as a three-dimensional material that supports phonon hydrodynamics at significantly higher temperatures (~100 K). The significant hydrodynamic nature of phonon transport in graphite is attributed to its strong intralayer sp2 hybrid bonding and weak van der Waals interlayer interactions. The hydrodynamic transport is manifested through drift motion of phonons, phonon Poiseuille flow, and second sound. Recent experiments demonstrating second sound up to 100K will be discussed.
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Presenters
Gang Chen
Department of Mechanical Engineering, Massachusetts Institute of Technology, Mechanical Engineering, Massachusetts Institute of Technology, Massachusetts Institute of Technology
Authors
Gang Chen
Department of Mechanical Engineering, Massachusetts Institute of Technology, Mechanical Engineering, Massachusetts Institute of Technology, Massachusetts Institute of Technology
Zhiwei Ding
Massachusetts Institute of Technology
Samuel Huberman
Massachusetts Institute of Technology
Ryan Duncan
Massachusetts Institute of Technology
Vazrik Chiloyan
Massachusetts Institute of Technology
Keith Adam Nelson
Massachusetts Institute of Technology, Department of Chemistry, Massachusetts Institute of Technology, Chemistry, MIT, MiT, Cambridge, MA 02139
