Effect of interaction range on phonon relaxation in Fermi-Pasta-Ulam β chain

Santhosh, G. ; Deepak Kumar, (2007) Effect of interaction range on phonon relaxation in Fermi-Pasta-Ulam β chain Physical Review E, 76 (2). 22102_1-22102 _4. ISSN 1063-651X

Full text not available from this repository.

Official URL: http://pre.aps.org/abstract/PRE/v76/i2/e022102

Related URL: http://dx.doi.org/10.1103/PhysRevE.76.022102

Abstract

We study the effect of increasing the range of interactions on phonon relaxation in a chain of atoms with quartic anharmonicity. The study is motivated by recent numerical studies, showing that the value of the exponent α characterizing the divergence of conductivity with system size apparently depends on the presence of second neighbor couplings. We perform a quantum calculation of the wave-vector (q) dependent relaxation rate Γ(q) in the second order perturbation theory. The nonanalytic dependence of Γ(q) arises due to small-q singularity of the collision integral. We find that Γ(q)∝Aq5/3+Bq2. This gives rise to an asymptotic value α=0.4, but the q2 terms lead to a higher apparent value of α at small sizes of the chain.

Item Type:Article
Source:Copyright of this article belongs to American Physical Society.
ID Code:9860
Deposited On:02 Nov 2010 10:36
Last Modified:31 May 2011 09:24

Repository Staff Only: item control page