Abstract
We introduce a novel approach to model heat transport in solids, based on the Green-Kubo theory of linear response. It naturally bridges the Boltzmann kinetic approach in crystals and the Allen-Feldman model in glasses, leveraging interatomic force constants and normal-mode linewidths computed at mechanical equilibrium. At variance with molecular dynamics, our approach naturally and easily accounts for quantum mechanical effects in energy transport. Our methodology is carefully validated against results for crystalline and amorphous silicon from equilibrium molecular dynamics and, in the former case, from the Boltzmann transport equation.
Highlights
We introduce a novel approach to model heat transport in solids, based on the Green-Kubo theory of linear response
In disordered systems the typical phonon mean free paths may be so short that the quasi-particle picture of heat carriers breaks down and Boltzmann transport equation (BTE) is no longer applicable, making it necessary to resort to molecular dynamics (MD), in either its nonequilibrium or equilibrium (EMD) flavors[2,3]
MD cannot account for quantum-mechanical effects[4], which are instead treated in BTE, making the treatment of heat transport for glasses in the quantum regime, i.e. below the Debye temperature, a methodological challenge
Summary
We introduce a novel approach to model heat transport in solids, based on the Green-Kubo theory of linear response. We present a novel approach to heat transport in insulating solids, which combines the Green–Kubo (GK) theory of linear response[3,5–8] and a quasi-harmonic description of lattice vibrations, resulting in a compact expression for the thermal conductivity, that unifies the BTE approach in the single-mode relaxation-time approximation (RTA) for crystals[2] and a generalization of the Allen-Feldman (AF) model for disordered system[9,10] that explicitly and naturally accounts for normal-mode lifetimes.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
