Different thermal conductance of the inter- and intrachain 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 intrachain interaction as well as by the interchain interaction. It is found that the intrachain interaction always enhance the thermal conductance. The interchain 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 intrachain interactions present different thermal properties in double-stranded lattices.