Universality or nonuniversality: Scaling for thermal transport in one dimension

Daxing Xiong

Published 2015-10-22Version 1

The universality classes of scaling for thermal transport in one-dimensional (1D) systems have been well suggested by various existing theories, and also indicated by numerical simulations. However, our direct dynamics simulations from two archetype 1D oscillator systems with quite different phonon dispersions here appear to support the nonuniversality. We show that, by varying anharmonicity and temperatures, the space-time scaling exponents can be feasibly tuned. The underlying picture is suggested to be understood by phonons performing various kinds of continuous-time random walks (in most cases, be the L\'{e}vy walks but not always), mainly induced by the peculiar phonon dispersions. The results and suggested mechanisms may provide insights into controlling the transport of heat in some 1D materials.