Our second paper of 2017 “Thermal conductivity decomposition in two-dimensional materials: Application to graphene” has just been accepted for publication in Physical Review B.
In this work we propose a decomposition of the microscopic heat current in atomistic molecular dynamics simulations into in-plane and out-of-plane components, corresponding to the in-plane and out-of-plane phonon dynamics, respectively. This decomposition allows a direct computation of the corresponding thermal conductivity components in two-dimensional materials. We apply this decomposition to study heat transport in suspended graphene, using both equilibrium and non-equilibrium molecular dynamics simulations. We show that the flexural component is responsible for about two thirds of the total thermal conductivity in unstrained graphene, and the acoustic flexural component is responsible for the logarithmic divergence of the conductivity when a sufficiently large tensile strain is applied, in accordance with my PRB Editors’ Suggestion paper with Prof. Davide Donadio in 2013.
The manuscript is a product of our ongoing collaboration with Dr. Zheyong Fan and Dr. Ari Harju at Aalto University, and a follow-up to our PRB paper in 2015.
The paper is available here. A preprint version is available here.