New Paradigm for Edge Reconstruction of Fractional States: Part Two - Noise

TL;DR

This paper investigates the complex interplay between neutral and charge modes in fractional quantum Hall states, revealing how non-equilibrium charge modes generate quantized shot noise through neutral mode interactions.

Contribution

It introduces a theoretical model explaining how non-equilibrium charge modes induce shot noise via neutral modes, addressing unresolved experimental contradictions.

Findings

Neutral modes influence charge mode fluctuations.

Non-equilibrium charge modes generate quantized shot noise.

Theoretical model matches experimental data.

Abstract

The recent, unexpected, findings of upstream neutral modes in particle-like fractional quantum Hall states, led to a realization that the nature of the neutral modes is far from being understood. Moreover, the observation of spatially separated of (at least) two downstream charge modes in hole-conjugate states (see Part One - Conductance), still faces unresolved contradictions between conductance and noise measurements. In this work we show how current fluctuations measured in various configurations shed light on the interplay between neutral and charge modes. We demonstrate that once one of the charge modes is taken out of equilibrium, counter-propagating neutral modes born in the equilibration process affect the upstream charge modes, giving rise to a novel mechanism for shot noise with quantized Fano factors. We present a theoretical model that accounts for most of the experimental observations.