Temperature dependence of thermal conductivity in 1D nonlinear latticesNianbei Li1 and Baowen Li1, 2
1 Department of Physics and Centre for Computational Science and Engineering, National University of Singapore - Singapore 117542, Republic of Singapore
2 NUS Graduate School for Integrative Sciences and Engineering - Singapore 117597, Republic of Singapore
received 19 December 2006; accepted in final form 20 March 2007; published May 2007
published online 17 April 2007
We examine the temperature dependence of thermal conductivity of one-dimensional nonlinear (anharmonic) lattices with and without on-site potential. It is found from computer simulation that the heat conductivity depends on temperature via the strength of nonlinearity. Based on this correlation, we make a conjecture in the effective phonon theory that the mean-free-path of the effective phonon is inversely proportional to the strength of nonlinearity. We demonstrate analytically and numerically that the temperature behavior of the heat conductivity is not universal for 1D harmonic lattices with a small nonlinear perturbation. The computer simulations of temperature dependence of heat conductivity in general 1D nonlinear lattices are in good agreement with our theoretic predictions. Possible experimental tests are discussed.
44.10.+i - Heat conduction.
44.05.+e - Analytical and numerical techniques.
05.60.-k - Transport processes.
© Europhysics Letters Association 2007