Phonon Thermal Transport Along the Chain Direction of Crystalline Polyethylene

It was once believed that the thermal conductivity (κ) in crystalline polyethylene (PE) is higher than 100 W/mK. Here, we applied the stochastic selfconsistent harmonic approximation (SSCHA) [1] combined with phonon Boltzmann transport equation to predict the κ of PE. Our calculation scheme incorporates the quantum, thermal, and anharmonic effects in force constants. It is found that the roomtemperature κ of PE is only ∼ 18 W/mK, which matches the previous thermoreflectance experiment well.