Ab-Initio Molecular Dynamics Study of Nano-Scale Thermal Energy Transport

Ab-initio molecular dynamics (MD) which employs density functional theory (DFT) is used to study thermal energy transport phenomena in nano-scale structures. Thermal equilibration in multiple thin layer structures with thicknesses less than 1 nanometer per layer is simulated. Different types of layer combinations are investigated. Periodic boundary conditions in all directions are used in all cases. Two neighboring layers are first set to different temperatures using Nose-Hoover thermostats, and then the process of energy equilibration is simulated with a “free run” (without any thermostat controlling the temperatures). The temperature evolutions in the two neighboring layers are computed. The atomic vibration power spectra are calculated and used to explain the phenomena observed in the simulation.