Hydrodynamic signatures in thermal transport in devices based on 2D materials: an ab initio study

Abstract

We investigate the features arising from hydrodynamic effects in graphene and phosphorene devices with finite heat sources, using ab initio calculations to go beyond Callaway's model and inform a full linearized scattering operator, and solving the phonon Boltzmann transport equation through energy-based deviational Monte Carlo methods. We explain the mechanisms that create those hydrodynamic features, showing that boundary scattering and the relation of sample dimensions to the nonlocal length are the determinant factors, regardless of the relative importance of normal versus resistive scattering. From this point of view, the nonlocal length reflects the ability of scattering to randomize the heat flux, and we show that approximations made on the scattering operator may have, through the value of nonlocal length, qualitative consequences on the signatures of hydrodynamic behavior.

16 pages, 19 figures

References in corpus (2)

• Direct Measurement of Room Temperature Non-diffusive Thermal Transport Over Micron Distances in a Silicon Membrane
• Co-existence of size-dependent and size-independent thermal conductivities in single layer black phosphorus

Cited by in corpus (4)

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• Vortices and backflow in hydrodynamic heat transport
• Local heat current flow in ballistic phonon transport of graphene nanoribbons
• Thermal transport in crystals: from the quantum Dyson equation to mesoscopic phonon hydrodynamics