How does pressure influence heat conduction for 1D nonlinear lattices with symmetric and asymmetric interactive potentials?

Abstract

Temperature and pressure are the two fundamental state parameters for the thermodynamical systems. It is known that the temperature can influence the heat conduction via the nonlinear properties of the 1D nonlinear lattices. However, it is not clear how does the pressure influence the heat conduction for these systems. In this work, the specific heat, sound velocity and phonon relaxation time, three key components of heat conductivity for the 1D nonlinear lattices are calculated via numerical simulations with applied external pressure. The results show that the dominant contribution for the change of heat conduction adjusted by the pressure comes from the phonon relaxation time. It is also found that the pressure influence of heat conduction is related with the potential symmetry of the 1D nonlinear lattices. It is the total pressure rather than the external pressure which mostly determines the heat conductivity.