Abstract
We propose a novel technique of molecular dynamics simulation to evaluate the relaxation time of phonons in solids for investigation of solid heat conductivity. The method is to observe relaxation behavior of the power spectrum of atomic velocities after energetically stimulating modes in a specific frequency region. The transient entropy S(t) is defined with the power spectrum based on non-equilibrium statistical mechanics. The obtained S(t) was found to be well fitted to a single exponential function, from which the frequency-dependent relaxation time can be evaluated.
