Spin-flip excitations and Stoner ferromagnetism in a strongly correlated quantum Hall system

TL;DR

This paper models spin-flip excitations in a strongly correlated quantum Hall system at filling factor nu=2, revealing how Coulomb interactions and Landau level mixing drive a transition from unpolarized to ferromagnetic states, with results aligning with experiments.

Contribution

It introduces a one-exciton theoretical approach to describe the Stoner transition in a quantum Hall system considering Landau level mixing effects.

Findings

Identification of the role of Coulomb interactions in spin-flip excitations.

Description of the Stoner transition from unpolarized to ferromagnetic states.

Comparison of theoretical results with experimental data confirms the model.

Abstract

Spin-flip excitations in a quantum Hall electron system at fixed filling factor nu=2 are modelled and studied under conditions of a strong Coulomb interaction when the `Landau level mixing' is a dominant factor determining the excitation energy. The `one-exciton' approach used for the purely electronic excitations in question allows us to describe the Stoner transition from the unpolarized/paramgnet state to the polarized/ferromagnet one. The theoretical results are compared with the available experimental data.