Heat equilibration of integer and fractional quantum Hall edge modes in graphene

TL;DR

This study investigates heat transport in graphene's quantum Hall states, revealing that integer and fractional edge channels can strongly equilibrate, affecting heat transport regimes and advancing understanding of edge physics in fractional quantum Hall systems.

Contribution

It demonstrates that integer quantum Hall edge channels significantly influence heat equilibration with fractional channels in graphene, a novel insight into edge state interactions.

Findings

Integer channels strongly equilibrate with fractional ones.

Heat transport regimes depend on edge electrostatics.

Results improve understanding of complex edge physics.

Abstract

Hole-conjugate states of the fractional quantum Hall effect host counter-propagating edge channels which are thought to exchange charge and energy. These exchanges have been the subject of extensive theoretical and experimental works; in particular, it is yet unclear if the presence of integer quantum Hall edge channels stemming from fully filled Landau levels affects heat equilibration along the edge. In this letter, we present heat transport measurements in quantum Hall states of graphene demonstrating that the integer channels can strongly equilibrate with the fractional ones, leading to markedly different regimes of quantized heat transport that depend on edge electrostatics. Our results allow for a better comprehension of the complex edge physics in the fractional quantum Hall regime.