Nonlinear thermal control in an N-terminal junction

TL;DR

This paper explores how heat flow in a molecular junction can be controlled, switched, and amplified by external reservoirs, highlighting the importance of anharmonic interactions for effective thermal regulation.

Contribution

It introduces a model demonstrating that anharmonic interactions enable tunable thermal control in molecular junctions, unlike harmonic models which lack controllability.

Findings

Harmonic models do not exhibit controllability of heat flow.

Anharmonic interactions enable strong dependence of conduction on gate parameters.

Thermal fluctuations induced by control reservoirs are key to modulation.

Abstract

We demonstrate control over heat flow in an N-terminal molecular junction. Using simple model Hamiltonians we show that the heat current through two terminals can be tuned, switched, and amplified, by the temperature and coupling parameters of external gating reservoirs. We discuss two models: A fully harmonic system, and a model incorporating anharmonic interactions. For both models the control reservoirs induce thermal fluctuations of the transition elements between molecular vibrational states. We find that a fully harmonic model does not show any controllability, while for an anharmonic system the conduction properties of the junction strongly depend on the parameters of the gates. Realizations of the model system within nanodevices and macromolecules are discussed.