Quantum thermal transport from classical molecular dynamics

Using a generalized Langevin equation of motion, quantum ballistic thermal transport is obtained from classical molecular dynamics. This is possible because the heat baths are represented by random noises obeying quantum Bose-Einstein statistics. The numerical method gives asymptotically exact results in both the low-temperature ballistic transport regime and high-temperature strongly nonlinear classical regime. The method can be thought of as a semi-classical approximation to the quantum transport problem. A one-dimensional quartic on-site model is used to demonstrate the crossover from ballistic to diffusive thermal transport.