Asymmetric Heat Conduction in One-Dimensional Electrical Lattice Model

For realization in experiments, we construct an electrical lattice model to investigate heat conduction. The lattice consists of two sublattices (SLs), of which one is nonlinear and the other is linear. It has been found that the energy transfer is asymmetric, that is, the energy can flow better through the system in one direction than in the opposite direction. Our analysis shows that the asymmetry results from the shift of the SL phonon band due to the nonlinearity, similar to that in the mechanical model of thermal rectification reported previously. The upper cutoff frequency of the nonlinear SL increases with the temperature, leading to overlapping with the stationary phonon band of the linear SL, so that the system conducts. According to our calculation, the asymmetry exists over a large range of temperatures and increases as the temperature difference between the heat baths increases, whereas it is independent of the coupling strength as long as it is weak and independent of the system size when it is not too large. Finally, some suggestions for the experimental realization of the lattice are given.