# Exchange-mediated dynamic screening in the integer quantum Hall regime

## TL;DR

This study uses self-consistent Hartree-Fock simulations to reveal how exchange interactions influence the spatial distribution of Landau levels in the integer quantum Hall regime, showing a Hund's rule-like behavior and reduced screening.

## Contribution

It demonstrates the significant role of exchange interactions in shaping Landau level distributions and screening effects in the integer quantum Hall regime, highlighting many-body effects on quantum-coherent length scales.

## Key findings

- Exchange interactions cause regions of full and empty Landau levels to coexist.
- Edge stripes of nearly half-odd filling appear at boundaries between regions.
- Screening of disorder and edge potential is significantly reduced compared to static models.

## Abstract

We study many-body interaction effects in the spatially-resolved filling factor ($\nu$) distribution for higher Landau levels (LLs) via self-consistent Hartree-Fock simulations in the integer quantum Hall (IQH) regime. Our results indicate a strong, interaction-induced tendency to avoid the simultaneous existence of partially filled spin-up and spin-down LLs. Rather, we find that such partially filled LLs consist of coexisting regions of full and empty LLs. At the boundaries between the regions of full and empty LLs, we observe edge stripes of nearly constant $\nu$ close to half-odd filling. This suggests that the exchange interaction induces a behavior similar to a Hund's rule for the occupation of the spin split LLs. The screening of the disorder and edge potential appears significantly reduced as compared to static Thomas-Fermi screening. Our results are consistent with a local, lateral $\nu$ dependence of the exchange-enhanced spin splitting. Hence, on quantum-coherent length scales as probed here, the electron system of the IQH effect behaves similar to a non-interacting single particle system - not because of the absence, but rather due to the dominance of many-body effects.