Thermal rectification in segmented Frenkel-Kontorova lattices with asymmetric next-nearest-neighbor interactions

TL;DR

This study investigates how asymmetric heat flow, or thermal rectification, occurs in segmented Frenkel-Kontorova lattices with both nearest and next-nearest neighbor interactions, revealing conditions that enhance rectification.

Contribution

It provides a detailed analysis of thermal rectification in these lattices, highlighting the role of NNN interactions and asymmetry, which is novel for this class of models.

Findings

Thermal rectification is larger with NNN interactions in the weak-coupling limit.

Rectification effectiveness increases with system size.

High asymmetry leads to distinct local heat flux behaviors.

Abstract

In this work we conduct an extensive study of the asymmetric heat flow, i.e. thermal rectification, present in the two-segment Frenkel Kontorova model with both nearest-neighbor (NN) and next-nearest-neighbor (NNN) interactions. We have considered systems with both high and low asymmetry and determined that, in the weak-coupling limit, thermal rectification is larger when NNN interactions are relevant. The behavior of the heat fluxes as a function of the coupling strength between the two segments is largely consistent with a well-defined rectification for larger system sizes. The local heat fluxes present a very different behavior for systems with high and low asymmetry. The results of this work may help in the design of molecular bridges, which have recently been shown to be able to function as thermal rectification devices.