Thermoforesis from generalized Caldeira-Leggett models

TL;DR

This paper generalizes the Caldeira-Leggett model to include thermal gradients, revealing signatures of thermophoresis and enabling quantum Brownian particle analysis in non-uniform environments.

Contribution

It introduces two models extending Caldeira-Leggett to thermal gradients, highlighting their advantages, limitations, and potential for quantum thermophoresis studies.

Findings

Signatures of thermophoresis observed in both models

Models can describe thermophoresis in quantum Brownian particles

Discussion of advantages and limitations of each model

Abstract

The standard Caldeira-Leggett model addresses the problem of Brownian motion in a thermal equilibrium environment. Here, we look for generalizations of the Caldeira-Leggett model to account for thermal gradients in the environment. We devise two types of models, and discuss the advantages and limitations of each one. From both models, we find signatures of thermophoresis, i.e., particle transport due to a thermal gradient. In principle, our models can be employed to describe thermophoresis in quantum Brownian particles, an open problem so far.