Edge-to-bulk transition of the IQHE at cleaved edge overgrown samples: a screening theory based experimental proposal

TL;DR

This paper proposes an experimental setup to observe the transition from bulk to edge in the integer quantum Hall effect by manipulating the edge potential profile, aiming to deepen understanding of QHE phenomena.

Contribution

It introduces a Hall bar design on cleaved edge overgrown wafers with a side gate to control edge potential profiles, enabling experimental exploration of the bulk-edge transition in QHE.

Findings

Plateau widths can be tuned and even eliminated by adjusting edge potential.

Controlling edge potential affects transport properties in the QHE regime.

Screening theory with Coulomb interactions predicts peculiar transport behaviors.

Abstract

In this work, we exploit the findings of the screening theory of the integer quantized Hall effect (QHE) based on the formation of the incompressible strips and its essential influence on the global resistances and propose certain experimental conditions to observe the bulk to edge transition of the QHE in a phenomenological model. We propose a Hall bar design on a cleaved edge overgrown wafer, which allows us to manipulate the edge potential profile from smooth to extremely sharp. For a particular sample design and by the help of a side gate perpendicular to the two dimensional electron system (2DES), it is shown that the plateau widths can be changed and even made to vanish when changing the edge potential profile. Such a control of the edge potential implies peculiar transport results when considering the screening theory, which includes direct Coulomb interaction explicitly. We think that, these experiments will shed new light on the understanding of the QHE.