Nonlocal Transport of Heat in Equilibrium Drift-Diffusion Systems

TL;DR

This paper investigates how heat transport in equilibrium quantum Hall edge states can exceed quantized values due to nonlocal interactions and reservoir effects, revealing a linear, equilibrium heat enhancement phenomenon.

Contribution

It demonstrates that local measurements can detect nonquantized heat in equilibrium edge states caused by nonlocal interactions and reservoir coupling, expanding understanding beyond traditional chiral Luttinger liquid theory.

Findings

Heat flux can surpass the quantized value in equilibrium conditions.

Nonlocal interactions and reservoir couplings induce a heat enhancement effect.

The phenomenon persists across different coupling models, including energy-conserving systems.

Abstract

The amount of heat an integer quantum Hall edge state can carry in equilibrium is quantized in universal units of the heat flux quantum $J_q= \frac{\pi k_B^2}{12 \hbar}T^2$ per edge state. We adress the question of how heat transport in realistic one dimensional devices can differ from the usual chiral Luttinger liquid theory. We show that a local measurement can reveal a nonquantized amount of heat carried by the edge states, despite a globally equilibrium situation. More specifically, we report a heat enhancement effect in edge states interacting with ohmic reservoirs in the presence of nonlocal interactions or chirality breaking diffusive currents. In contrast to a nonequilibrium, nonlinear drag effect, we report an equilibrium, linear phenomenon. The chirality of the edge states creates additional correlations between the reservoirs, reflected in a higher than quantum heat flux in the chiral channel. We show that for different types of coupling the enhancement can be understood as static or dynamical backaction of the reservoirs on the chiral channel. We show that our results qualitatively hold by replacing the dissipative ohmic reservoirs by an energy conserving mesoscopic capacitor and consider the respective transmission lines for different types of interaction.