Effect of Electron Correlation on the Integer Quantum Hall Effect

TL;DR

This study numerically explores how increasing electron correlation strength affects the quantization of transverse conductance in the integer quantum Hall effect, revealing that stronger correlations can degrade quantization due to modulations in system parameters.

Contribution

It provides new insights into the impact of electron correlation on the integer quantum Hall effect using numerical simulations on a lattice model.

Findings

Increased correlation strength degrades conductance quantization.

Correlation induces periodic modulations in hopping parameters and site energies.

Electron correlation significantly influences conductivity in the quantum Hall regime.

Abstract

We numerically investigate the effect of electron correlation on the integer quantum Hall effect in a square lattice. Increasing the correlation strength via the effective onsite repulsion parameter $U$ degrades the quantization of $\nu = 1$ transverse conductance due to the interplay of correlation and the external magnetic field, which together induce periodic modulations in renormalized hopping parameters and site energies. Overall, this work demonstrates that the strength of electron correlation can significantly impact conductivity in the integer quantum Hall regime.