EFFECT OF TEMPERATURE ON INTRINSIC LOCALIZED MODES IN ANHARMONIC LATTICES

We study the effect of temperature on Intrinsic Localized Modes (ILM) in anharmonic lattices. An approach is proposed based on the Method of the Unsymmetrized Self-Consistent Field (USF). The special case of an odd-parity mode in an anharmonic linear chain with Mie–Lennard–Jones potential is investigated in more detail. We find that in the weak anharmonic approximation, an increasing of temperature does not change the pattern of the mode, leading to a very small decreasing of the displacement amplitudes and a decreasing of the mode frequency. The frequency of the mode increases with increasing of both the repulsion and attraction indexes. This effect is more sensitive to the repulsion index.