Different thermal conductance of the inter- and intra-chain interactions in a double-stranded molecular structure

A double-stranded system, modeled by a Frenkel-Kontorova lattice, is studied through nonequilibrium molecular dynamics simulations. We have investigated the thermal conductance influenced by the intra-chain interaction as well as by the inter-chain interaction. It is found that the intra-chain interaction always enhance the thermal conductance. The inter-chain interaction, however, has a positive effect on the thermal conductance in the case of strong nonlinear potential, and has a negative effect on the thermal conductance in the case of weak nonlinear potential. This phenomenon can be explained by the transition of thermal transport mode and the phonon band shift of the particles. It is suggested that the inter-and intra-chain interactions present different thermal properties in double-stranded lattices.