title: Tunable heat conduction through coupled Fermi-Pasta-Ulam chains.
abstract: We conduct a study on heat conduction through coupled Fermi-Pasta-Ulam (FPU) chains by using classical molecular dynamics simulations. Our attention is dedicated to showing how the phonon transport is affected by the interchain coupling. It has been well accepted that the heat conduction could be impeded by the interchain interaction due to the interface phonon scattering. However, recent theoretical and experimental studies suggest that the thermal conductivity of nanoscale materials can be counterintuitively enhanced by the interaction with the substrate. In the present paper, by consecutively varying the interchain coupling intensity, we observed both enhancement and suppression of thermal transport through the coupled FPU chains. For weak interchain couplings, it is found that the heat flux increases with the coupling intensity, whereas in the case of strong interchain couplings, the energy transport is found to be suppressed by the interchain interaction. Based on the phonon spectral energy density method, we attribute the enhancement of the energy transport to the excited phonon modes (in addition to the intrinsic phonon modes), while the upward shift of the high-frequency phonon branch and the interface phonon-phonon scattering account for the suppressed heat conduction.
authors: Department of Physics and the Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Beijing), Beijing Normal University, Beijing 100875, China.
authors: Ruixia
authors: R
authors: Su
authors: Institute of Applied Physics and Computational Mathematics, Beijing 100088, China.
authors: Zongqiang
authors: Z
authors: Yuan
authors: Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
authors: Jun
authors: J
authors: Wang
authors: Department of Physics and the Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Beijing), Beijing Normal University, Beijing 100875, China.
authors: Zhigang
authors: Z
authors: Zheng