Universal heat superdiffusion in one-dimensional nonequilibrium lattices

We propose a generalized Fourier's law, based on recent mode-coupling calculations, for one-dimensional nonlinear lattices in nonequilibrium simulations, where the boundaries are kept at different temperatures. Though not useful for the typical textbook numerical examples, we are able to demonstrate numerically the theory for an anharmonic lattice with force field parameters similar to those of realistic low-dimensional structures such as covalently bonded molecular chains or carbon nanotubes, specifically showing that the asymptotic heat conductivity is described by the mode-coupling theory in good approximation, without any adjustable parameter. Published by the American Physical Society 2024