Molecular heat transport across a time-periodic temperature gradient

TL;DR

This paper investigates how oscillating temperature gradients influence heat transport in molecular lattices, revealing controllable energy storage and transfer mechanisms through analytical and simulation methods.

Contribution

It introduces a theoretical framework combining stochastic energetics and Green's functions to analyze vibrational heat flow under time-periodic temperature differences.

Findings

Oscillating gradients induce controllable energy storage and release.

Thermal conductance can be tuned by frequency, waveform, and amplitude.

The framework applies broadly to vibrational heat transmission in molecular systems.

Abstract

The time-periodic modulation of a temperature gradient can alter the heat transport properties of a physical system. Oscillating thermal gradients give rise to behaviors such as modified thermal conductivity and controllable time-delayed energy storage that are not present in a system with static temperatures. Here, we examine how the heat transport properties of a molecular lattice model are affected by an oscillating temperature gradient. We use analytical analysis and molecular dynamics simulations to investigate the vibrational heat flow in a molecular lattice system consisting of a chain of particles connected to two heat baths at different temperatures, where the temperature difference between baths is oscillating in time. We derive expressions for heat currents in this system using a stochastic energetics framework and a nonequilibrium Green's function approach that is modified to treat the nonstationary average energy fluxes. We find that emergent energy storage, energy release, and thermal conductance mechanisms induced by the temperature oscillations can be controlled by varying the frequency, waveform, and amplitude of the oscillating gradient. The developed theoretical approach provides a general framework to describe how vibrational heat transmission through a molecular lattice is affected by temperature gradient oscillations.