Heat Transport Hysteresis Generated through Frequency Switching of a Time-Dependent Temperature Gradient

TL;DR

This study investigates how frequency switching of a time-dependent temperature gradient influences heat transport hysteresis in nanoscale systems, revealing complex hysteresis behaviors with potential applications in thermal neuromorphic devices.

Contribution

It introduces a stochastic energetics framework to analytically and numerically analyze the effects of frequency switching on heat transport hysteresis in nanoscale models.

Findings

Frequency switching alters hysteresis curve shapes.

Emergence of pinched and multi-loop hysteresis patterns.

Analytical results agree with molecular dynamics simulations.

Abstract

A stochastic energetics framework is applied to examine how periodically shifting the frequency of a time-dependent oscillating temperature gradient affects heat transport in a nanoscale molecular model. We specifically examine the effects that frequency switching, i.e., instantaneously changing the oscillation frequency of the temperature gradient, has on the shape of the heat transport hysteresis curves generated by a particle connected to two thermal baths, each with a temperature that is oscillating in time. Analytical expressions are derived for the energy fluxes in/out of the system and the baths, with excellent agreement observed between the analytical expressions and the results from nonequilibrium molecular dynamics simulations. We find that the shape of the heat transport hysteresis curves can be significantly altered by shifting the frequency between fast and slow oscillation regimes. We also observe the emergence of features in the hysteresis curves such as pinched loops and complex multi-loop patterns due to the frequency shifting. The presented results have implications in the design of thermal neuromorphic devices such as thermal memristors and thermal memcapacitors.