2ème atelier international
J. Phys. IV France 05 (1995) C4-461-C4-474
Spontaneous Localization of Vibrational EnergyD.W. Brown1 and L. Bernstein2
1 Institute for Nonlinear Science, University of California, San Diego La Jolla, CA 92093-0402, U.S.A.
2 Department of Mathematics, Box 8085, Idaho State University, Pocatello, ID 83209-8085, U.S.A.
In this paper we illustrate a number of the characteristic manifestations of soft anharmonicity in the behavior of lattice vibrations, both in and out of thermal equilibrium. In particular, we focus on various ways in which vibrational energy may come to be localized as a consequence of anharmonicity, even in defect-free lattices. These include the "overpopulation" of anharmonic vibrations in thermal equilibrium, the inhibition of dispersion, and the enhancement of spatial coherence. The relevance of the spontaneous localization of vibrational energy in the formation of "hot spots" is discussed, with particular emphasis on the unstable evolution of high-amplitude initial conditions as may be found in initiating shocks.
© EDP Sciences 1995