Thermal rectifying effect in two dimensional anharmonic lattices

TL;DR

This paper investigates the thermal rectification effect in two-dimensional anharmonic lattices, demonstrating significant rectifying efficiency linked to spectral matching and mismatch, with potential experimental observability.

Contribution

It introduces the study of thermal rectification in 2D FK and FPU lattices, highlighting the spectral mechanism behind the effect and quantifying rectifying efficiency.

Findings

Rectifying efficiency reaches about two orders of magnitude.

The effect depends on temperature and gradient.

Spectral matching/mismatch explains the mechanism.

Abstract

We study thermal rectifying effect in two dimensional (2D) systems consisting of the Frenkel Kontorva (FK) lattice and the Fermi-Pasta-Ulam (FPU) lattice. It is found that the rectifying effect is related to the asymmetrical interface thermal resistance. The rectifying efficiency is typically about two orders of magnitude which is large enough to be observed in experiment. The dependence of rectifying efficiency on the temperature and temperature gradient is studied. The underlying mechanism is found to be the match and mismatch of the spectra of lattice vibration in two parts.