Heat generation and transport due to time-dependent forces

TL;DR

This paper derives an exact analytical expression for heat transport in solids under arbitrary time-dependent forces using NEGF, revealing how heat current relates to system properties and bath interactions.

Contribution

It introduces a novel NEGF-based analytical framework for heat transport under time-dependent forces, including effects of multiple baths and nonlinear interactions.

Findings

Heat current relates to the system's density of states.

In ballistic transport, heat current is independent of bath temperature.

Energy absorption occurs only when bath frequency resonates with applied frequency.

Abstract

We study heat transport for solids in the presence of arbitrary time-dependent force. Using nonequilibrium Green's function (NEGF) approach we present an exact analytical expression of current for the linear system. We found that the heat current can be expressed in terms of the displacement of the atoms in the center and the self energy of the baths. We carry out the calculation for the oscillatory driven force and study the steady state properties for one-dimensional linear chain and two-dimensional square lattice. We found that the heat current is related to the density of states of the system and is independent of the bath temperature in ballistic transport. The baths absorb energy only when their intrinsic frquency resonates with the applied frequency We also generalize the problem for multiple heat baths with different temperatures. We also discuss the effect due to nonlinear interactions in the center.