1999/10/26 by Andrea Lippi, A. Lippi, Roberto Livi +3
Engineering · Materials Science · Physics and Astronomy · #Adhesion, Friction, and Surface Interactions #Advanced Thermodynamics and Statistical Mechanics #Chaotic Dynamics (nlin.CD) #FOS: Physical sciences #Material Dynamics and Properties #chao-dyn #nlin.CD
paper · pdf · doi:10.48550/arxiv.chao-dyn/9910034
21 pages, 8 postscript figures
arxiv created 1999/10/26 · openalex publication_date 1999/10/26 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The divergence of the heat conductivity in the thermodynamic limit is investigated in 2d-lattice models of anharmonic solids with nearest-neighbour interaction from single-well potentials. Two different numerical approaches based on nonequilibrium and equilibrium simulations provide consistent indications in favour of a logarithmic divergence in "ergodic", i.e. highly chaotic, dynamical regimes. Analytical estimates obtained in the framework of linear-response theory confirm this finding, while tracing back the physical origin of this \sl anomalous transport to the slow diffusion of the energy of long-wavelength effective Fourier modes. Finally, numerical evidence of \sl superanomalous transport is given in the weakly chaotic regime, typically found below some energy density threshold.