Universality of phonon transport in nanowires dominated by surface roughness

摘要

We analyze, both theoretically and numerically, the temperature-dependent thermal conductivity k of two-dimensional nanowires with surface roughness. Although each sample is characterized by three independent parameters, the diameter (width) of the wire, the correlation length, and the strength of the surface corrugation, our theory predicts that there exists a universal regime where k is a function of a single combination of all three model parameters. Numerical simulations of propagation of acoustic phonons across thin wires confirm this universality and predict a d~(1/2) dependence of k on the diameter d.