Thermal Transport in Twisted Bilayer Graphene: An Equilibrium Molecular Dynamics Study

Abstract

Twisted bilayer graphene (tBLG) is two graphene layers placed on top of each other with a twist angle, making it has tunable thermal properties. In this paper, we report an analysis of thermal conductivity ($\kappa$), phonon density of states, and specific heat capacity of tBLG with various twist angles over a range of temperatures using equilibrium molecular dynamics simulations based on the Green-Kubo method. Simulation shows that stacking and twisting graphene layers lead to a decrease in the thermal conductivity, with the highest $\kappa$ at around room temperature owned by the tBLG with a twist angle of 3.89$^{\circ}$ followed by 16.43$^{\circ}$ and 4.41$^{\circ}$. We also perform quantum correction to the simulation results to show the process of increasing thermal conductivity at low temperatures.