Compressibility stripes for mesoscopic quantum Hall samples

TL;DR

This paper numerically studies how disorder and electron-electron interactions influence the electronic compressibility in the integer quantum Hall effect, revealing non-linear screening, charging effects, and phase diagram implications.

Contribution

It provides new numerical insights into the interplay of disorder and interactions, highlighting effects like g-factor enhancement and overscreening in quantum Hall samples.

Findings

Manifestations of non-linear screening and charging effects around integer filling factors

Observation of g-factor enhancement and overscreening in Landau bands

Good agreement with experimental results supports the role of electron-electron interactions

Abstract

We numerically investigate the interplay of disorder and electron-electron interactions in the integer quantum Hall effect. In particular, we focus on the behaviour of the electronic compressibility as a function of magnetic field and electron density. We find manifestations of non-linear screening and charging effects around integer filling factors, consistent with recent imaging experiments. Our calculations exhibit $g$-factor enhancement as well as strong overscreening in the centre of the Landau bands. Even though the critical behaviour appears mostly unaffected by interactions, important implications for the phase diagram arise. Our results are in very good agreement with the experimental findings and strongly support the relevance of electron-electron interactions for understanding integer quantum Hall physics.