Observation of phonon Poiseuille flow in isotopically-purified graphite ribbons

TL;DR

This paper reports the first experimental observation of phonon Poiseuille flow in isotopically purified graphite ribbons, supported by a theoretical model, advancing understanding of phonon hydrodynamics in graphitic materials.

Contribution

It demonstrates phonon Poiseuille flow in a microscale graphite ribbon using a novel experimental platform and theoretical modeling, confirming hydrodynamic heat transport in this material.

Findings

Phonon Poiseuille flow observed in 5 μm-wide graphite ribbon

Experimental results align with kinetic theory based on first-principles

Supports potential for heat manipulation applications in graphitic materials

Abstract

In recent times, the unique collective transport physics of phonon hydrodynamics motivates theoreticians and experimentalists to explore it in micro- and nanoscale and at elevated temperatures. Graphitic materials have been predicted to facilitate hydrodynamic heat transport with their intrinsically strong normal scattering. However, owing to the experimental difficulties and vague theoretical understanding, the observation of phonon Poiseuille flow in graphitic systems remains challenging. In this study, based on a microscale experimental platform and the pertinent occurrence criterion in anisotropic solids, we demonstrate the phonon Poiseuille flow in a 5 {\mu}m-wide suspended graphite ribbon with purified 13C isotope concentration. Our observation is well supported by our theoretical model based on a kinetic theory with fully first-principles inputs. Thus, this study paves the way for deeper insight into phonon hydrodynamics and cutting-edge heat manipulating applications.