Non-uniform Brillouin zone sampling for thermal transport in layered materials

Abstract

Lattice thermal conductivity in layered materials is typically dominated by long-wavelength phonon modes and is traditionally computed by uniform phonon sampling in the Brillouin zone, which is often computationally demanding. In this work, we develop and implement a non-uniform Brillouin zone sampling approach to efficiently predict the thermal conductivity of layered materials within the Boltzmann transport equation framework. Using single-layer graphene and bulk MoS2 as case studies, our method optimizes phonon sampling through two key parameters: grid cutoff distance, which defines a dense phonon mesh near the Γ-point, and grid ratio, which sets the resolution of the coarser grid in the remaining regions. This selective sampling reduces the computational cost involved in phonon scattering calculation by a factor of 10 while maintaining thermal conductivity prediction accuracy within 12% compared with the uniform grid approach.