Equilibration and Universal Heat Conduction in Fermi-Pasta-Ulam Chains

Trieu Mai, Abhishek Dhar, Onuttom Narayan
2007 Physical Review Letters  
It is shown numerically that for Fermi Pasta Ulam (FPU) chains with alternating masses and heat baths at slightly different temperatures at the ends, the local temperature (LT) on small scales behaves paradoxically in steady state. This expands the long established problem of equilibration of FPU chains. A well-behaved LT appears to be achieved for equal mass chains; the thermal conductivity is shown to diverge with chain length N as N^(1/3), relevant for the much debated question of the
more » ... stion of the universality of one dimensional heat conduction. The reason why earlier simulations have obtained systematically higher exponents is explained.
doi:10.1103/physrevlett.98.184301 pmid:17501580 fatcat:x64eqfm2ijbb7dmdgewuc2tktm