Modulating Low-dimensional Heat Conduction By Stress

Along with the rapidly developing of nanotechnology,especially the appearing of carbon nanotubes and graphene,low-dimensional heat conduction problem has attracted intense attention over last decades.This paper theoretically study the mechanism of the stress's impact on low-dimensional heat conduction,predicting heat conduction's variation trend with stress in real materials.Firstly,this paper take traditional one-dimensional(1d)nonlinear interaction lattice,Fermi-Pasta-Ulam-?(FPU-p)lattice,into consideration,aiming to find the influence of stress on its heat conduction behavior.Theoretical analysis shows the rule of potential's change with stress,indicating stress turn symmetric interaction FPU-?potential into asymmetric interaction FPU-?? potential.According to recent years' results about 1d heat conduction,this implies qualitative change in heat conduction under thermodynamic limit.It not only changes heat current's fluctuating and relaxation law,but also may lead a normal heat conduction behavior.Meanwhile,further analysis shows stretching and compression have symmetric impact on FPU-? lattice's potential change,i.e.,FPU-? lattice have same heat conduction behavior with same rate of stretching or compression.Subsequent numerical simulations confirm this analytical conclusion.Then this paper study the heat conduction behavior of graphene with stress.Theoretical analysis shows that if the motion of the particles of graphene are restricted in plane(flexural-free graphene),the heat conductivity of graphene decrease with stretching and increase with compression,and subsequent numerical simulations confirm this theoretical conclusion.While,if the motion of the particles of graphene is allowed to move out of plane(flexural-induced graphene),simulation results show the heat conductivity of graphene decrease both with stretching and compression.This kind of change can be explained by the scattering of the phonons by the graphene's bending caused by compression.This paper's results provide mechanisms for understanding modulating of low-dimensional heat conduction by stress,and guidance for related experiments.