Partial equilibration of integer and fractional edge channels in the thermal quantum Hall effect

TL;DR

This paper investigates how partial equilibration of edge channels affects thermal conductance measurements in quantum Hall systems, explaining deviations from ideal quantization at certain filling factors and reconciling experimental results with theoretical models.

Contribution

It introduces a model of partial equilibration of integer and fractional edge channels to explain thermal conductance anomalies in quantum Hall effects.

Findings

Partial equilibration explains imperfect quantization at ν=8/3.

Thermal conductance can increase by two quanta at ν=8/5.

Reconciliation of experimental data with PH-Pfaffian and anti-Pfaffian orders.

Abstract

Since the charged mode is much faster than the neutral modes on quantum Hall edges at large filling factors, the edge may remain out of equilibrium in thermal conductance experiments. This sheds light on the observed imperfect quantization of the thermal Hall conductance at $\nu=8/3$ and can increase the observed thermal conductance by two quanta at $\nu=8/5$. Under certain unlikely but not impossible assumptions, this might also reconcile the observed thermal conductance at $\nu=5/2$ with not only the PH-Pfaffian order but also the anti-Pfaffian order.