Mechanical control of heat conductivity in microscopic models of dielectrics

TL;DR

This paper explores how external mechanical loads can significantly control heat conductivity in one-dimensional dielectric models, revealing mechanisms for substantial reduction of heat transfer through structural modifications.

Contribution

It introduces mechanical control methods for heat conductivity in microscopic dielectric models, demonstrating large reductions via chain length variation and external forcing effects.

Findings

Heat conduction can be reduced nearly five-fold by changing chain length.

External forcing can make a single-well potential effectively double-well, reducing heat conduction by two orders of magnitude.

Mechanical models can be used to control heat transport in biological and microscale systems.

Abstract

We discuss a possibility to control a heat conductivity in simple one-dimensional models of dielectrics by means of external mechanical loads. To illustrate such possibilities we consider first a well-studied chain with degenerate double-well potential of the interparticle interaction. Contrary to previous studies, we consider varying length of the chain with fixed number of particles. Number of possible energetically degenerate ground states strongly depends on the overall length of the chain, or, in other terms, on average length of the link between neighboring particles. These degenerate states correspond to mechanical equilibrium, therefore one can say that the transition between them mimics to some extent a process of plastic deformation. We demonstrate that such modification of the chain length can lead to quite profound (almost five-fold) reduction of the heat conduction coefficient. Even more profound effect is revealed for a model with single-well non-convex potential. It is demonstrated that in certain range of constant external forcing this model becomes "effectively"\ double-well, and has a multitude of possible states of equilibrium for the same value of the external load. Thus, the heat conduction coefficient can be reduced by two orders of magnitude. We suggest a mechanical model of a chain with periodic double-well potential, which allows control over the heat conduction. The models considered may be useful for description of heat transport in biological macromolecules and for control of the heat transport in microsystems.