Experimentally Motivated Order of Length Scales Affect Shot Noise

TL;DR

This paper investigates how the order of length scales influences shot noise in quantum point contacts, revealing distinct universal features in thermal equilibration regimes for different quantum Hall edge states.

Contribution

It classifies thermal equilibration regimes in quantum Hall edges using dc current correlations, highlighting the impact of length scale order on shot noise.

Findings

Charge equilibration length is much shorter than thermal equilibration length.

Universal features differ between particle-like and hole-like edge states.

Distinct thermal regimes can be identified via shot noise measurements.

Abstract

Shot noise at a conductance plateau in a quantum point contact (QPC) can be explained by considering equilibrations at the quantum Hall edges. The indication from recent experiments is that the charge equilibration length is much shorter than the thermal equilibration length. We discuss how this discovery gives rise to different thermal equilibration regimes in the presence of full charge equilibration. In this work, we classify these distinct regimes via dc current-current correlations (electrical shot noise) at definite experimentally found (or possible) QPC conductance plateaus for the edges of integer, particle-like, and hole-like filling fractions in a two dimensional electron gas. Our analyses show that distinct universal features arise among the different thermal equilibration regimes for the edges of particle-like and hole-like states.