Thermal rectification in one-dimensional lattices with nonlinear system–reservoir coupling

In this work we study the thermal rectification properties of a one-dimensional, mass-graded oscillator lattice with nonlinear system–reservoir couplings. For the case of a harmonic oscillator chain the system presents no rectification at high temperatures and a very weak one for low temperatures as the asymmetric, nonlinear interaction with the thermal reservoirs is increased. The observed rectification rapidly degrades as either the thermal bias or mass asymmetry increase in magnitude. For an anharmonic oscillator Fermi–Pasta–Ulam lattice the rectification increases for the aforementioned conditions, and is maximized when only nonlinear system-reservoir interactions are considered. These latter ones correspond to the case of multiplicative noise affecting the boundaries of the lattice.