MCBTE: A variance-reduced Monte Carlo solution of the linearized Boltzmann transport equation for phonons

• DOI: 10.1016/j.cpc.2021.108003
• Publication Date: 2021-04-20T12:57:02Z
• Authors: Abhishek Pathak; Avinash Pawnday; Aditya Prasad Roy; Amjad J. Aref; Gary F. Dargush; Dipanshu Bansal
• Keywords: Ballistic conduction

MCBTE solves the linearized Boltzmann transport equation for phonons in three dimensions using a variance-reduced Monte Carlo solution approach. The algorithm is suited for both transient and steady-state analysis of thermal transport in structured materials with size features in the nanometer to hundreds of microns range. The code is portable and integrated with both first-principles density functional theory calculations and empirical relations for the input of phonon frequency, group velocity, and mean free path required for calculating the thermal properties. The program outputs space- and time-resolved temperature and heat flux for the transient study. For the steady-state simulations, the frequency-resolved contribution of phonons to temperature and heat flux is written to the output files, thus allowing the study of cumulative thermal conductivity as a function of phonon frequency or mean free path. We provide several illustrative examples, including ballistic and quasi-ballistic thermal transport, the thermal conductivity of thin films and periodic nanostructures, to demonstrate the functionality and to benchmark our code against available theoretical/analytical/computational results from the literature. Moreover, we parallelize the code using the Matlab Distributed Computing Server, providing near-linear scaling with the number of processors.<br/>43 pages, 13 figures<br/>