Linear and nonlinear response for radiative heat transfer in many-body systems

TL;DR

This paper develops a response theory combining perturbation and fluctuational-electrodynamics to analyze temperature dynamics in many-body systems under time-dependent external heating, revealing emergent dynamical phenomena.

Contribution

It introduces a novel formalism for temperature response in many-body systems driven by external sources, enabling efficient analysis of dynamical thermal behavior.

Findings

Derived explicit formulas for temperature and phase shifts.

Demonstrated temperature dynamics in systems with one to three degrees of freedom.

Identified phenomena like amplification, attenuation, and delays in temperature responses.

Abstract

A theory of temperature dynamics in many-body systems driven by time-dependent external sources is introduced. The formalism based on the combination of the perturbation theory and the fluctuational-electrodynamics approach in many-body systems. By using response theory, explicit formula for the temperature and phase shifts is derived and expressed in terms of the amplitude and phase of external power sources. Although the proposed method is highly efficient because it can skip the transient response, it is valid when external powers are weak. As an illustration of this theoretical framework, we have shown the dynamics of temperatures in one, two, and three degree of freedom systems driven by sine wave input powers. Finally, we highlighted some emergent phenomena arising from purely dynamical many-body effects, including amplification, attenuation, delaying or accelerating temperature responses. This work could find important applications in the domain of dynamical thermal management at the nanoscale.