Nondiffusive phonon transport in complex diamond microstructures and nanostructures
Phys. Rev. B 114, 225424 – Published 29 October, 2026
DOI: https://doi.org/10.1103/45l6-6d47
Abstract
The ultrahigh thermal conductivity of diamond, relevant to the momentum-conserving phonon normal process, holds exceptional promise for advanced micro/nanoscale thermal management. However, efficient modeling of collective phonon transport in complex three-dimensional diamond structures remains challenging. Here, we develop a computational approach for phonon transport in complex diamond micro- and nanostructures by directly solving the phonon Boltzmann transport equation under Callaway's dual relaxation model with first-principles inputs. As a result, our model provides a good quantitative explanation of the thermal conductivities of diamond nanowires, nanobeams and cuboids. Furthermore, we analyze the effects of size and temperature on mode-resolved phonon hydrodynamic transport in natural and isotopically purified diamond microfilms. Finally, the computational framework is applied to porous diamond structures to reveal the effects of neck width and isotopic concentration on nondiffusive phonon transport. This work thus promotes both efficient modeling and physical insights into collective phonon transport in diamond micro- and nanostructures, offering guidance for future experimental measurements and engineering applications.
