Thermal Conductivity of Rotator Chains with a Double-Barrier Interaction Potential

Abstract

The results of numerical simulation of the thermal conductivity of a one-dimensional chain of rotators with a double-barrier interaction potential between the nearest neighbors are presented. It is shown that the internal barrier that separates topologically nonequivalent degenerate states has a substantial effect on the temperature dependence of the thermal conductivity of the chain. At low heights of this barrier in the low-temperature region, the main contribution to the increase in the thermal conductivity is made by nonlinear normal modes. With an increase in the temperature, the increase in the thermal conductivity is limited by the occurrence of local above-barrier transitions that prevent energy transfer along the chain. With an increase in the internal barrier height, the contribution of nonlinear normal modes to the energy transfer process decreases and the system exhibits the temperature behavior typical of systems of conventional rotators.