Fluctuation bounds on charge and heat diffusion

TL;DR

This paper investigates how thermal fluctuations impose lower bounds on charge and heat diffusion constants in systems with conserved energy and charge, highlighting their importance in understanding transport coefficient limits.

Contribution

It introduces the concept that thermal fluctuations set fundamental lower bounds on diffusion constants in thermoelectric systems with conserved energy and charge.

Findings

Thermal fluctuations can establish lower bounds on diffusion constants.

Fluctuation corrections are significant in systems lacking momentum conservation.

Implications for bounds on thermoelectric transport coefficients.

Abstract

We study thermal fluctuation corrections to charge and heat conductivity in systems with locally conserved energy and charge, but without locally conserved momentum. Thermal fluctuations may naturally lead to a lower bound on diffusion constants for thermoelectric transport, and need to be taken into account when discussing potential bounds on transport coefficients.